Determinants and Histopathologic Patterns of Lung Cancer at St. Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia: A Six Year Retrospective Case‒Control Study, 2024

Determinants and Histopathologic Patterns of Lung Cancer at St. Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia: A Six Year Retrospective Case‒Control Study, 2024 | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Determinants and Histopathologic Patterns of Lung Cancer at St. Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia: A Six Year Retrospective Case‒Control Study, 2024 Amanuel Yeneneh Teka, Bacha Mirkena Dhabi, Tsigehana Sisay Mekonnen, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8089607/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 13 You are reading this latest preprint version Abstract Background Lung cancer is the leading cause of cancer-related death globally, accounting for 1.8 million deaths annually. Its incidence is increasing in low- and middle-income countries (LMICs), including Ethiopia, where it comprises 1.5% of all cancers. Despite this, lung cancer remains locally underresearched. Objective To assess the determining factors and histopathological patterns of lung cancer at St. Paul’s Hospital Millennium Medical College (SPHMMC), Addis Ababa, Ethiopia. Method A hospital-based case‒control study involving 105 participants (35 cases and 70 controls) selected from histopathology-confirmed lung biopsies was conducted from January 2024 to January 2025. The Data were cleaned via EPI Data and analyzed via SPSS version-26. Descriptive statistics were used to summarize the findings, and Fisher’s exact test with odds ratios was used to identify determinants, as the sample size was insufficient for logistic regression modeling. Results The mean age was 43.83 years, with near-gender parity (M:F ratio of 1.1:1); there was a slight female predominance (0.94:1). Most patients (61.1%) were diagnosed with stage IV disease. Common symptoms included cough (81.0%), dyspnea (68.6%), and chest pain (59.0%). Radiologic findings revealed mass lesions in 67.6% of the patients. Adenocarcinoma was the predominant histologic subtype (46%). Smoking (OR = 4.50, p = 0.001) and biomass fuel use (OR = 2.20, p = 0.048) were significant risk factors. Conclusion Lung cancer at SPHMMC affects relatively young patients with near gender parity. Late-stage presentation and strong associations with smoking and biomass exposure highlight the need for early detection, smoking cessation, and clean energy initiatives. biomass use lung cancer histopathology retrospective analysis smoking prevalence Ethiopia Figures Figure 1 Figure 2 Figure 3 1. Introduction 1.1. Background Lung cancer is one of the most lethal malignancies, worldwide and is responsible for more deaths than any other cancer type. According to the Global Cancer Observatory, it accounts for approximately 11.6% of all cancer diagnoses and 18.4% of cancer-related deaths worldwide [ 1 ]. The disease is characterized by its aggressive nature, rapid progression, and poor prognosis, especially when it is diagnosed at advanced stages. While historically associated with high-income countries due to industrial exposure and tobacco use, recent trends show a rising incidence in low- and middle-income nations, including Ethiopia [ 2 ]. Lung cancer is the most commonly diagnosed cancer worldwide, with over 2 million new cases annually [ 3 ]. It is broadly classified into non-small_cell lung cancer (NSCLC) and small_cell lung cancer (SCLC). NSCLC accounts for approximately 85% of cases and includes adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. SCLC, although less common, is more aggressive and often presents with early metastasis [ 4 ]. Adenocarcinoma has become the most prevalent subtype globally, particularly among nonsmokers and women. This shift is attributed to changes in smoking habits, increased exposure to environmental pollutants, and improved diagnostic techniques [ 5 ]. Tobacco smoking remains the leading risk factor for lung cancer and is responsible for nearly 85% of cases [ 6 ]. The risk increases with the duration and intensity of smoking. Passive smoking also contributes significantly, especially among women and children. In many low-income countries, biomass fuels (wood, charcoal, and dung) are used for cooking and heating. Prolonged exposure to smoke from these sources has been linked to chronic respiratory diseases and lung cancer [ 7 ]. Women are disproportionately affected by their domestic roles. Exposure to carcinogens such as asbestos, silica, radon, and diesel exhaust increases the risk of lung cancer. Urban air pollution, particularly fine particulate matter (PM2.5), has also been implicated [ 8 ]. Although less common, genetic predisposition plays a role in lung cancer development. Mutations in genes such as EGFR, ALK, and KRAS are associated with specific subtypes and influence treatment response [ 9 ]. Studies from African countries have shown variability in histologic subtypes. In Egypt and Nigeria, adenocarcinoma is the most common type, followed by squamous cell carcinoma [ 10 ]. Late-stage presentation is common due to limited access to healthcare and diagnostic services. A study at Tikur Anbessa Specialized Hospital (TASH) reported adenocarcinoma as the dominant subtype, with most cases being diagnosed at stage IV [ 11 ]. Another study using machine learning identified coughing blood, air pollution, and obesity as predictive features for lung cancer [ 12 ]. However, these studies lacked control groups and comprehensive risk factor analysis. In Ethiopia, the use of biomass fuels for cooking and heating, limited access to healthcare, and increasing tobacco consumption contribute to the increasing burden of lung cancer. Despite this, lung cancer remains underdiagnosed and underreported due to the lack of national cancer registries, inadequate diagnostic infrastructure, and low public awareness. Histopathologic evaluation remains the cornerstone of diagnosis, yet access to biopsy and pathology services is limited to a few tertiary institutions. SPHMMC is one of the few centers in Ethiopia with consistent histopathologic reporting and electronic medical records. This study leverages data from SPHMMC to explore the determinants and histopathological patterns of lung cancer, aiming to fill a critical gap in local cancer epidemiology. 1.2. Statement of the Problem Despite the increasing burden of lung cancer in Ethiopia, there is a significant lack of localized data on its epidemiology, histopathologic subtypes, and associated risk factors. Most existing studies are descriptive, single-center reports that do not employ robust analytical designs. As a result, public health interventions remain generic and poorly targeted. Patients often present at advanced stages due to delayed diagnosis, misinterpretation of symptoms, and limited access to imaging and pathology services. Moreover, the contributions of environmental and lifestyle factors such as biomass fuel exposure, smoking, and occupational hazards remain poorly understood in the Ethiopian context. Without evidence-based insights, clinicians face challenges in early detection, risk stratification, and treatment planning. This study addresses these gaps by analyzing lung cancer cases diagnosed at SPHMMC over a six-year period, using a case‒control design to identify key determinants and describe histopathological patterns. The findings aim to inform clinical practice and guide public health policy. 1.3. Rationale of the Study Understanding the determinants and histopathological characteristics of lung cancer in Ethiopia is essential for several reasons. First, it enables the identification of high-risk populations, particularly those exposed to tobacco smoke and biomass fuels. Second, it provides insights into the most prevalent histologic subtypes, which can guide diagnostic protocols and treatment decisions. Third, it highlights systemic barriers to early diagnosis, such as limited access to imaging and pathology services. By generating evidence from a tertiary care center with reliable pathology data, this study contributes to the national discourse on cancer control. It supports the development of targeted awareness campaigns, resource allocation for diagnostic infrastructure, and the integration of lung cancer screening into primary healthcare. Furthermore, the findings can serve as a baseline for future multicenter studies and inform the creation of a national cancer registry. 2. Methods and Materials 2.1. Study Area and Period The study was conducted at SPHMMC, which is located on Swaziland Street in Addis Ababa, Ethiopia. Established by a Council of Ministers resolution in 2010, the hospital and medical school traced their origins to 1969, were founded by Emperor Haile Selassie, and officially opened in 2007. Serving more than 5 million people, the SPHMMC provides comprehensive inpatient and outpatient care across various specialties. Its Pathology Center has been operational since 2014 and, is among the few advanced facilities in the country, archiving specimens from multiple institutions. It delivers fine-needle aspiration cytology (FNAC) services to more than 7,000 patients annually and performs approximately 6,000 biopsies each year. The study period extended from January 2, 2024 to January 1, 2025. This duration was selected to accommodate the low incidence of lung cancer within the institution and to ensure sufficient time for excluding malignancies in the control group. 2.2. Study Design A hospital-based case‒control study design was employed. 2.3. Source population The source population included all patients who had lung biopsy samples submitted to the pathology department of SPHMMC between September 2018 and January 2024. 2.4. Study Population with Eligibility Criteria The study population included patients who underwent lung biopsy at SPHMMC between September 2018 and January 2024, with complete histopathologic and clinical records. Inclusion criteria : Patients with histopathologically confirmed lung cancer (cases) Patients with nonmalignant lung biopsy results (controls) Availability of complete demographic and clinical data Exclusion criteria : Patients with equivocal or inconclusive biopsy results Incomplete pathology reports or missing key clinical information 2.5. Sample size determination The sample size was calculated via a double population proportion formula, assuming a 95% confidence level, 80% power, and a 1:2 case-to-control ratio. On the basis of previous studies indicating a smoking prevalence among lung cancer patients of approximately 60% and among controls of 20%, the minimum required sample size was 105 (35 cases and 70 controls). This was adjusted for feasibility and availability of complete records. 2.6. Sampling Technique Cases were selected consecutively from histopathologically confirmed lung cancer patients. Controls were selected via simple random sampling from eligible noncancer patients who underwent lung biopsy during the same period. 2.6. Operational definitions • Case • A patient with histopathologically confirmed lung cancer diagnosis. Control : A patient with nonmalignant lung biopsy findings. Biomass Fuel Exposure : Use of wood, charcoal, dung, or crop residues for cooking or heating. Smoking history : Self-reported history of tobacco use, including cigarettes or traditional forms. Lung cancer : histopathologically confirmed cases of primary lung cancer at the SPHMMC pathology department 2.7. Variables Dependent Variable : Histopathologically confirmed lung cancer diagnosis Independent Variables : Age Sex Residence Smoking history Biomass fuel exposure Family history of cancer Occupational exposure Clinical symptoms Radiologic findings Tumor location Cancer stage Histopathologic subtypes 2.8. Data collection procedure Data were collected retrospectively from electronic pathology records and patient charts. A structured checklist was used to extract relevant variables. Histopathologic reports were reviewed by certified pathologists, and clinical data were verified through chart abstraction. 2.9. Data Processing and Analysis The data were entered into SPSS version 26 for analysis. Descriptive statistics were used to summarize demographic and clinical characteristics. Fisher’s exact test was applied to assess associations between categorical variables due to the small sample size. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to identify significant determinants of lung cancer. 2.10. Data Quality Assurance To ensure data quality, the checklist was pretested on a small sample before full data collection. Double data entry was performed to minimize errors. Histopathologic diagnoses were cross-checked by two independent pathologists. Incomplete records were excluded from analysis. 2.11. Ethical considerations Ethical clearance for this study was obtained from IRBs of Y12HMC and SPHMMC. Because the study was retrospective in nature, and relied exclusively on anonymized patient records without direct involvement of human subjects, the IRBs formally waived the requirement for individual informed consent. Confidentiality and anonymity were rigorously maintained throughout the data collection, with no personally identifiable information recorded or disclosed, ensuring that dissemination of the findings adheres to established ethical standards. 2.12. Dissemination Plan The findings of this study were disseminated to SPHMMC, the Ethiopian Ministry of Health, and relevant stakeholders through presentations. After publication, copies will also be made available to academic institutions and libraries for reference. 3. Results 3.1. Sociodemographic characteristics A total of 105 patients were included in the study, comprising 35 histopathologically confirmed lung cancer patients and 70 controls. The mean age of all participants was 43.83 years (SD ± 14.2), with the average age of the lung cancer patients being 45.2 years. The age distribution revealed that the majority of cases (54.3%) fell within the 41– 60 years age group, followed by 28.6% in the 21– 40 years age range. Only 17.1% of the patients were above 60 years of age, indicating a relatively younger cohort than the global trend. The gender distribution showed a nearly equal split, with a male-to-female ratio of 1.1:1 overall. Among lung cancer cases, females slightly outnumbered males (M:F ratio 0.94:1), which contrasts with global data that typically show male predominance. Residency data were incomplete, with 39.1% missing. Among the available data, 27.6% of the participants were urban dwellers, and 33.3% were rural residents. Insert Table 1 here Table 1 Sociodemographic Characteristics of Lung Cancer Patients at SPHMMC, Addis Ababa Ethiopia, September 2018 to January 2024. Variables Categories Case/Control Lung Ca Non-Lung Ca Total Age 0–25 1(2.9%) 17(24.3%) 18(17.1%) 25–50 13(37.1%) 30(42.9%) 43 (41.0%) 50–75 17(48.6%) 23(32.9%) 40(38.1%) 75–100 4(11.4%) 0 4(3.8%) Gender Male 17(48.6%) 38(54.3%) 55(52.4%) Female 18(51.4%) 32(45.7%) 50 (47.6%) Residency area Urban 10(28.5%) 19(27.1%) 29(27.6%) Rural 11(31.4%) 24(34.2%) 35(33.3%) Missing 14(40.1%) 27(38.7%) 41(39.1%) Sociodemographic characteristics of lung cancer patients at SPHMMC, Addis Ababa Ethiopia, from September 2018 to January 2024. 3.2. Clinical presentation The most frequently reported symptoms among lung cancer patients were chronic cough (81%), dyspnea (68.6%), chest pain (59%), and weight loss (80%). Fever was noted in 34.3% of the patients, whereas hemoptysis occurred in 22.9%. These symptoms are consistent with advanced pulmonary disease and often overlap with other respiratory conditions, contributing to diagnostic delays. Radiologic findings revealed mass lesions in 67.6% of the patients, followed by consolidation (15%), cavitation (10%), and pleural effusion (7.4%). These findings are often nonspecific and require histopathological confirmation. Among the 18 patients with documented stage disease, 61.1% were diagnosed with stage IV disease, 22.2% with stage III disease, and 16.7% with stage II disease. No patients were diagnosed with stage I disease. Metastasis was present in 50% of the patients, with the contralateral lung and liver being the most common sites. Insert Table 2 here Table 2 Clinical Features of Lung Cancer Patients at SPHMMC, Addis Ababa, Ethiopia, September 2018 to January 2024. Variables Case/Control Lung Ca Non-Lung Ca Total Hospitalization status Yes 11(31.40%) 40(57.10%) 51(48.60%) No 24(68.60%) 30(42.90%) 54(51.40%) Cough Yes 34(97.10%) 51(72.90%) 85(81%) No 1(2.90%) 19(27.10%) 20(19%) Shortness of Breath Yes 31(88.60%) 41(58.60%) 72(68.60%) No 4(11.40%) 29(41.40%) 33(31.40%) Chest pain Yes 21(60%) 41(58.60%) 62(59%) No 14(40%) 29(41.40%) 43 (41%) Hemoptysis Yes 15(42.90%) 12(17.10%) 27(25.70%) No 20(57.10%) 58(82.90%) 78(74.30%) Weight Loss Yes 28(80%) 26(37.10%) 54(51.40%) No 7(20%) 44(62.90%) 51(48.60%) Fever Yes 12(34.30%) 19(27.10%) 31(29.50%) No 23(65.70%) 51(72.90%) 74(70.50%) Method of Biopsy Bronchoscopy 6(17.10%) 7(10%) 13(12.40%) Lobectomy 6(17.10%) 15(21.40%) 21(20%) CNB 22(62.90%) 23(32.90%) 45(42.90%) Resection 1(2.90%) 11(15.70%) 12(11.40%) Thoracotomy 0 14(20%) 14(13.30%) Orientation of Tumor Right 23(65.70%) 37(52.90%) 60(57.10%) Left 9(25.70%) 30(42.90%) 39(37.10%) Bilateral 3(8.60%) 3(4.30%) 6(5.70%) Clinical features of lung cancer patients at SPHMMC, Addis Ababa, Ethiopia, from September 2018 to January 2024. Insert Fig. 1 here Radiologic findings of lung cancer patients at SPHMMC, Addis Ababa, Ethiopia, from September 2018 to January 2024. 3.3. Histopathologic patterns Histopathologic analysis revealed that adenocarcinoma was the most prevalent subtype, accounting for 46% of cases. Squamous cell carcinoma and small cell carcinoma each represented 11% of the cases. Other subtypes included poorly differentiated carcinoma (9%), large cell carcinoma (6%), and rare variants such as carcinoid tumors. Tumor location analysis revealed that 57.1% of cases involved the right lung, with the upper lobe being the most frequently affected site. This distribution may be influenced by anatomical and airflow dynamics, although further investigation is needed. Insert Fig. 2 here Histopathologic patterns of the case group in the assessment of lung cancer at SPHMMC, Addis Ababa, Ethiopia, from September 2018 to January 2024. Insert Fig. 3 here Histopathologic patterns of the control group in the assessment of lung cancer SPHMMC, Addis Ababa, Ethiopia, from September 2018 to January 2024. 3.4. Determinants of Lung Cancer Smoking was reported by 57.1% of the lung cancer patients, whereas only 5.7% of the controls smoked. This yielded an odds ratio (OR) of 4.5 (95% CI: 2.1–9.8, p = 0.001), confirming a strong association between tobacco use and lung cancer. Biomass fuel exposure was reported by 40% of the cases and 20% of the controls, resulting in an OR of 2.2 (95% CI: 1.01–4.8, p = 0.048). No participants reported a family history of lung cancer. Occupational exposure data were incomplete and excluded from analysis. Insert Table 3 here Table 3 Fisher’s Exact Test Analysis of Determinant Factors for Lung Cancer at SPHMMC, Addis Ababa, Ethiopia, September 2018 to January 2024. Variables Lung Ca Fisher's Exact p-value Unadjusted OR (95%CI) Yes No Gender Male 17(48.6%) 38(54.3%) 0.679 0.85(0.5,1.47) Female 18(51.4%) 32(45.7%) Smoking Yes 20(57.1%) 4(5.7%) 0.001 4.50(2.75,7.350)** No 15(42.9%) 66(94.3%) 1 Biomass use Yes 14(40%) 14(20%) 0.048 2.20(1.293,5.173)** No 5(14.3%) 17(24.3%) 1 Age Category 50 21(60%) 23(32.9%) 1 Residency Urban 10(28.5%) 19(27.1%) 1.00 1.09(0.54,2.21) Rural 11(31.4%) 24(34.2%) History of Alcoholism Yes 6(17.1%) 10(14.3%) 0.77 1.15(0.57,2.317) No 29(82.9%) 60(85.7%) **Significant association at p-value of less than 0.05 Fisher’s exact test analysis of determinant factors for lung cancer at SPHMMC, Addis Ababa, Ethiopia, from September 2018 to January 2024. 4. Discussion Globally, lung cancer remains the most frequently diagnosed cancer and the leading cause of cancer-related death, accounting for 2.1 million new cases and 1.8 million deaths annually [ 13 ]. Although lung cancer ranks lower in incidence than other cancers do in Ethiopia, its mortality burden is significant. The Addis Ababa cancer registry places lung carcinoma as the sixth most common malignancy among males [ 14 ]. The findings of this study reveal a distinct epidemiologic profile of lung cancer at SPHMMC, with patients presenting at a younger age (mean 45.2 years) compared with studies in Bangladesh (mean 59.57 years) [ 15 ] and TASH (median 54 years) [ 16 ]. This younger age distribution may reflect earlier exposure to risk factors or diagnostic delays due to limited healthcare access. The gender distribution in this study shows near parity (M:F ratio 0.94:1), which contrasts with global trends where males are disproportionately affected [ 17 ]. This may be attributed to environmental exposures such as biomass fuel use, which is more common among women in Ethiopia. The residency data revealed a slight rural predominance among the cases, suggesting a possible link to indoor air pollution and limited access to early diagnostic services. Clinically, the most common symptoms were cough (97.1%), shortness of breath (88.6%), and chest pain (60%), which is consistent with findings from studies in Egypt [ 18 ], India [ 19 ], and TASH [ 16 ]. The average symptom duration was 7.9 months, indicating delayed presentation. Notably, 14.3% of the patients were initially treated for tuberculosis, highlighting the diagnostic overlap between TB and lung cancer. Metastasis was present in 37% of the patients, with distant spread in 61.5%, primarily to the contralateral lung and liver. Stage IV disease was documented in 31.4% of the patient, which was lower than the 76.2% reported in TASH [ 16 ] but still indicative of late-stage disease. Radiologic findings were dominated by mass lesions (82.9%), followed by consolidation and combined presentations. The tumors were more frequently located in the right lung (57.1%), which aligns with the anatomical predispositions noted in other studies [ 20 ]. Histopathologically, adenocarcinoma was the most prevalent subtype (46%), followed by squamous cell carcinoma and small cell lung cancer (each 11%). This pattern mirrors global shifts toward adenocarcinoma dominance, especially among nonsmokers and women [ 21 ]. Compared with older studies from Turkey [ 22 ], Iran [ 23 ], and South Africa [ 24 ] where squamous cell carcinoma was more common, the current trend reflects changing environmental exposures and diagnostic practices. Smoking was strongly associated with lung cancer in this study, with an odds ratio of 4.5. This aligns with international findings and reinforces tobacco use as the primary risk factor [ 25 ]. The smoking prevalence among cases (57.1%) is higher than national estimates but comparable to rates reported in Turkey [ 21 ] and Iran [ 23 ]. Biomass fuel use also showed a significant association (OR = 2.2), underscoring its role as a local environmental risk factor. This finding is particularly relevant in Ethiopia, where traditional cooking methods are widespread [ 26 ]. The absence of reported family history and incomplete occupational exposure data limit conclusions about genetic and workplace-related risks. 5. Strengths and Limitations This study is the first of its kind in Ethiopia to employ a case‒control design for investigating lung cancer determinants. It provides a comprehensive analysis of histopathological patterns and risk factors, contributing to the limited body of local evidence. However, several limitations must be acknowledged. The small sample size reduces the statistical power and limits generalizability. Missing data on residency, occupation, and staging hindered deeper analysis. The retrospective design is subject to information bias, and reliance on chart reviews may have led to underreporting of exposures. Despite these limitations, the study offers important insights and lays the groundwork for future research. 6. Conclusion This study highlights the distinctive profile of lung cancer at SPHMMC, Ethiopia, which is characterized by a younger patient demographic (mean age: 45.2 years) and near-gender parity (male‑to‑female ratio: 0.94:1), diverging from global trends. In this relatively low‑smoking population, biomass fuel use (OR = 2.2) emerged as a significant risk factor, whereas smoking (OR = 4.5) remained the predominant determinant. Adenocarcinoma was the major histologic type (46%), which is consistent with the increasing global incidence among nonsmokers. The high proportion of late‑stage diagnoses (61.1% stage IV) underscores systemic delays in detection and access to care. These findings reinforce the urgent need for earlier diagnostic pathways, investment in cleaner energy initiatives to reduce indoor air pollution, and targeted smoking cessation programs. Abbreviations CCC Coordinated and Comprehensive Cancer Care CIs confidence intervals DALY Disability Adjusted Life Years EFMOH Ethiopian Federal Ministry of Health EGFR Epidermal growth factor receptor FNAC Fine needle aspiration cytology GLOBCON Global Cancer Observatory IRB Institutional Review Board NSCLC Non-Small Cell Lung Cancer OR Odds ratio SCC Squamous cell carcinoma SCLC Small cell lung cancer SD Standard deviation SPHMMC St. Paul's Hospital Millennium Medical College SPSS Statistical Package for Social Sciences TASH Tikure Anbesa Specialized Hospital USA United States of America WHO World Health Organization WSE Wood Smoke Exposure Y12HMC Yekatit 12 Hospital Medical College Declarations Ethical Approval and Consent to Participate Ethical clearance for this study was obtained from the IRBs of Y12HMC and SPHMMC. Because the study was retrospective in nature, and relied exclusively on anonymized patient records without direct involvement of human subjects, the IRBs formally waived the requirement for individual informed consent. Confidentiality and anonymity were rigorously maintained throughout the data collection, with no personally identifiable information recorded or disclosed, ensuring that dissemination of the findings adheres to established ethical standards. Consent for Publication: Not applicable. Availability of Data and Materials: The corresponding author will make the research data and supporting materials available upon reasonable request from the editorial team. Competing Interests: The authors declare that they have no conflicts of interest. The sole interest is academic dissemination through publication. Funding : This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Author contributions Dr Amanuel Yeneneh Teka: conceptualization, methodology, writing original draft, data curation, formal analysis, investigation. Dr Bacha Mirkena Dhabi: Writing review and editing, writing manuscript, data collection and data entry, formal analysis Dr Tsigehana Sisay Mekonnen: Writing original draft, data collection, data entry, formal analysis Yimer Seid Yimer: Supervision, Project administration, Validation Acknowledgment First and foremost, we express our deepest gratitude to God for granting us the strength and perseverance to complete this research—from proposal development to final analysis. We extend our sincere appreciation to Y12HMC and its Department of Public Health for facilitating this academic opportunity. We are also profoundly grateful to SPHMMC for granting access to patient records and supporting the implementation of this study in their facility. We would like to acknowledge the Pathology Department of SPHMMC for their invaluable collaboration. Our heartfelt appreciation is also extended to the Patient Record Keeping Unit of SPHMMC for their assistance in data retrieval and documentation. We further extend our appreciation to Mr. Mohammed Abdu Yimam, a cyber security expert, for his technical guidance and support in ensuring data protection throughout the study. References What Is Cancer? [Internet]. National Cancer Institute. Cancer.gov. 2021. Available from: https://www.cancer.gov/about-cancer/understanding/what-is-cancer Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA: A Cancer Journal for Clinicians. 2021; 71(3):209 – 49. Awedew AF, Asefa Z, Belay WB. National Burden and Trend of Cancer in Ethiopia, 2010 2019: a systemic analysis for Global burden of disease study. Sci Rep. 2022;12 (1). UpToDate.Uptodate.com. 2023.Available from: https://www.uptodate.com/contents/overview-of-the-initial-treatment-and prognosis-of lung-cancer?source = bookmarks_widget. Siegel RL, Miller KD, Fuchs HE, Jemal A, Cancer Statistics. 2021. CA: A Cancer Journal for Clinicians. 2021; 71(1):7–33. Barta JA, Powell CA, Wisnivesky JP. Global Epidemiology of Lung Cancer. Annals Global Health. 2019; 85 (1). Article R, Tigeneh W, Molla A, Abreha A, Assefa M, Citation: Tigeneh W. (2015) Pattern of Cancer in Tikur Anbessa Specialized Hospital Oncology Center in Ethiopia from 1998 to 2010. Int J Cancer Res Mol Mech. 2015; 1(1). Muir CS, Waterhouse J, Mack TM, Powell J, Whelan S, editors. Cancer Incidence in Five Continents. Vol, X. Lyon, France: International Agency for Research on Cancer. Prevalence | Tobacco Atlas [Internet]. Tobacco Atlas. 2022 [cited 2023 Jan 15]. Available from: https://tobaccoatlas.org/challenges/prevalence/ Mengesha SD, Teklu KT, Weldetinsae A, Serte MG, Kenea MA, Dinssa DA et al. Tobacco use prevalence and its determinate factor in Ethiopia- finding of the 2016 Ethiopian GATS. BMC Public Health. 2022; 22(1). UpToDate [Internet]. Uptodate.com. 2023 [cited 2023 Jan 15]. Available from: https://www.uptodate.com/contents/cigarette-smoking-and-other-possible-risk-factors for-lung-cancer/abstract/35–44 Boloker G, Wang C, Zhang J. Updated statistics of lung and bronchus cancer in United States (2018). J Thorac Disease. 2018;10(3):1158–61. Hosseini M, Naghan PA, Karimi S, SeyedAlinaghi S, Bahadori M, Khodadad K, et al. Environmental risk factors for lung cancer in Iran: a case-control study. Int J Epidemiol. 2009;38(4):989–96. Ganesh. A case–control study of risk factors for lung cancer in Mumbai, India. Asian Pac J cancer prevention: APJCP. 2024; 12(2). Houston K, Henley S, Li J, White M, Richards T. Lung Cancer. HHS Public Access. 2014;86(1):22–8. Guarga L, Ameijide A, Marcos-Gragera R, Carulla M, Delgadillo J, Borràs JM et al. Trends in lung cancer incidence by age, sex and histology from 2012 to 2025 in Catalonia (Spain). Sci Rep. 2021; 11(1). Demirci E, Daloglu F, Gundogdu C, Calik M, Sipal S, Akgun M. Incidence and Clinicopathologic Features of Primary Lung Cancer: A North-Eastern Anatolia Region Study in Turkey (2006–2012). Asian Pac J Cancer Prev. 2013;14(3):1989–93. Ugur Gonlugur TE, Gonlugur M, Kaptanoglu, Cinar Z. The changing epidemiological trends for carcinoma of the lung in Turkey. Saudi Med J. 2008;29(5):749–53. Gupta R, Chowdhary I, Singh PORIGINALARTICLE, Clinical. Radiological and Histological profile of Primary Lung Carcinomas. JK SCIENCE 146 www.kscience.org. 2015; 17(3). Chakrabortty R, Siddiqua DR, Paul SK, Rahman S, Biswas SK. Histopathological Patterns of Lung Cancer along with Clinico-Radiological Correlation in a Tertiary Care Hospital in Bangladesh. J Med. 2022;23(2):126–31. Hajmanoochehri F, Mohammadi N, Zohal MA, Sodagar A, Ebtehaj M. Epidemiological and Clinicopathological Characteristics of Lung Cancer in a Teaching Hospital in Iran. Asian Pac J Cancer Prev. 2014;15(6):2495–500. Akl YM, Emam RH, Sabry IM, Ali AA. Clinico-pathological profile of bronchogenic carcinoma cases presented to Chest Department, Cairo University in the last 10 years. Egypt J Chest Dis Tuberculosis. 2013;62(4):705–12. Johannesburg S. Africa. Southern African Journal of Infectious Diseases A Study of lung cancer in Johannesburg, South Africa.Southern African. J Infect Dis. 2015;29(1):43–7. Missaoui N, Hmissa S, Landolsi H, Korbi S, Joma W, Anjorin A, Ben Abdelkrim S. Beizig N;Mokni M. Lung cancer in central Tunisia: epidemiology and clinicopathological features. Asian Pac J cancer prevention: APJCP.2016; 12(9). Zakkouri FA, Saloua O, Halima A, Rachid R, Hind M, Hassan E. Smoking, passive smoking and lung cancer cell types among women in Morocco: analysis of epidemiological profiling of 101 cases. BMC Res Notes. 2015; 8(1). Li D, Shi J, Liang D, Ren M, He Y. Lung cancer risk and exposure to air pollution: a multicenter North China case–control study involving 14604 subjects. BMC Pulm Med. 2023; 23(1). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 31 Mar, 2026 Reviews received at journal 14 Mar, 2026 Reviewers agreed at journal 13 Mar, 2026 Reviews received at journal 22 Dec, 2025 Reviewers agreed at journal 21 Dec, 2025 Reviews received at journal 19 Dec, 2025 Reviewers agreed at journal 19 Dec, 2025 Reviewers agreed at journal 19 Dec, 2025 Reviewers invited by journal 12 Dec, 2025 Editor assigned by journal 08 Dec, 2025 Editor invited by journal 19 Nov, 2025 Submission checks completed at journal 18 Nov, 2025 First submitted to journal 18 Nov, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8089607","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":560304270,"identity":"8c4f790a-319e-4d3e-9cee-7be0f9801595","order_by":0,"name":"Amanuel Yeneneh Teka","email":"","orcid":"","institution":"St. Paul’s Hospital Millennium Medical College","correspondingAuthor":false,"prefix":"","firstName":"Amanuel","middleName":"Yeneneh","lastName":"Teka","suffix":""},{"id":560304271,"identity":"135fec2a-e7c6-4957-9872-32af00bd2268","order_by":1,"name":"Bacha Mirkena Dhabi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAx0lEQVRIiWNgGAWjYBACNgbGBwwfGBgSYFxitDAbMM5A0UJYG7MBMw9JWvikmxkf2/y5k6c77TDQhWWHGfjlGwg4TOYws3Fu27Nis9tpQBeeO8wg2UbAFjaJ/GPSuQ2HE7fdzmFg5m07zGBwjKCWZDZpiz9QLX+BWuyJ0sLABtXCCLKFkPeBWpgNe9ueAbWkGRzsOZfOI3EsAb8W+RnJjA9+/LkD1JL88MGPMms5/uYDBKyBgANwkoco9XAto2AUjIJRMAqwAgBFfUH002oM3gAAAABJRU5ErkJggg==","orcid":"","institution":"Addis Ababa Burn Emergency and Trauma/AaBET Hospital, Affiliate of St. Paul’s Hospital Millennium Medical College","correspondingAuthor":true,"prefix":"","firstName":"Bacha","middleName":"Mirkena","lastName":"Dhabi","suffix":""},{"id":560304279,"identity":"c5a9806a-a65d-43cf-8713-59cc9176e134","order_by":2,"name":"Tsigehana Sisay Mekonnen","email":"","orcid":"","institution":"St. Paul’s Hospital Millennium Medical College","correspondingAuthor":false,"prefix":"","firstName":"Tsigehana","middleName":"Sisay","lastName":"Mekonnen","suffix":""},{"id":560304281,"identity":"3d1774f8-3080-4100-a230-6b5800e8a1ca","order_by":3,"name":"Yimer Seid Yimer","email":"","orcid":"","institution":"Addis Ababa University, St. Paul’s Hospital Millennium Medical College (SPHMMC)","correspondingAuthor":false,"prefix":"","firstName":"Yimer","middleName":"Seid","lastName":"Yimer","suffix":""}],"badges":[],"createdAt":"2025-11-11 18:38:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8089607/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8089607/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":98780039,"identity":"23507894-c843-4b2d-a4da-73606659d9ce","added_by":"auto","created_at":"2025-12-22 12:30:59","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":36779,"visible":true,"origin":"","legend":"","description":"","filename":"Figures.docx","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/507eb6036462e3384b460c1d.docx"},{"id":98749241,"identity":"7210cce0-7c2a-4e2f-a4a5-89783c9b7357","added_by":"auto","created_at":"2025-12-22 09:00:54","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":56863,"visible":true,"origin":"","legend":"","description":"","filename":"RevisedManuscript.docx","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/c7d883670aa03f50dda6d879.docx"},{"id":98749243,"identity":"4c73764c-fbc2-4f54-a98e-4aefd6945c5f","added_by":"auto","created_at":"2025-12-22 09:00:55","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":23542,"visible":true,"origin":"","legend":"","description":"","filename":"Tables.docx","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/3194d21f6d38f4dc9e92405b.docx"},{"id":98749245,"identity":"b963c5b1-8a90-48ca-b966-2909bf6d16da","added_by":"auto","created_at":"2025-12-22 09:00:55","extension":"json","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":7227,"visible":true,"origin":"","legend":"","description":"","filename":"82a13fc8236b464c84b91c91a7036c89.json","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/9d5bf54049c200bf81df6346.json"},{"id":98749244,"identity":"c1c04c71-c116-4a85-a41a-b2818efc643d","added_by":"auto","created_at":"2025-12-22 09:00:55","extension":"xml","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":98695,"visible":true,"origin":"","legend":"","description":"","filename":"82a13fc8236b464c84b91c91a7036c891enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/d2ab1bbd0279d7e3e8f11c14.xml"},{"id":98749247,"identity":"dc2ee005-b27e-4dbf-af2e-0205b8f97dad","added_by":"auto","created_at":"2025-12-22 09:00:55","extension":"png","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":13441,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/d718aea6c0229e7eee6f56b6.png"},{"id":98749248,"identity":"84219c5f-fae5-4b57-8f91-ef6ec1fe5095","added_by":"auto","created_at":"2025-12-22 09:00:55","extension":"png","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":6374,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/9fec5ab95bbd793c2fdf4f64.png"},{"id":98777219,"identity":"123eb5c8-80b6-447f-ab26-de5347e5f604","added_by":"auto","created_at":"2025-12-22 12:26:00","extension":"xml","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":96489,"visible":true,"origin":"","legend":"","description":"","filename":"82a13fc8236b464c84b91c91a7036c891structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/e7f5b4a6409005809367a043.xml"},{"id":98777371,"identity":"9b21d9c1-f917-4823-8a32-861524432eeb","added_by":"auto","created_at":"2025-12-22 12:26:36","extension":"html","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":108988,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/23766365ac314345802a6aba.html"},{"id":98779962,"identity":"91ccc70a-13fb-44eb-b92a-1804ad89f526","added_by":"auto","created_at":"2025-12-22 12:30:57","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":105802,"visible":true,"origin":"","legend":"\u003cp\u003eRadiologic Findings of Lung Cancer Patients at SPHMMC, Addis Ababa, Ethiopia, September 2018 to January 2024.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/ea777e02dc710dcdf5340c54.png"},{"id":98749238,"identity":"9984b164-c6ab-40ae-b727-c7fff19e88c1","added_by":"auto","created_at":"2025-12-22 09:00:54","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":106363,"visible":true,"origin":"","legend":"\u003cp\u003eHistopathologic Patterns of Case group in the Assessment of Lung Cancer at SPHMMC, Addis Ababa, Ethiopia, September 2018 to January 2024.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/60c28b6664b0e661f92d0d02.png"},{"id":98749242,"identity":"9ca0420a-c6a8-4a6f-a83c-56c6727a87d0","added_by":"auto","created_at":"2025-12-22 09:00:55","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":120436,"visible":true,"origin":"","legend":"\u003cp\u003eHistopathologic Patterns of Control group in the Assessment of Lung Cancer at St. Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia, September 2018 to January 2024.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/eb31be8a2203ef9438c48ca0.png"},{"id":98783477,"identity":"9a96fc4b-756b-4b0f-bb3c-59552ba40f38","added_by":"auto","created_at":"2025-12-22 12:42:01","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1365473,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8089607/v1/b267df32-77e7-4f7f-adbb-9a5338208178.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Determinants and Histopathologic Patterns of Lung Cancer at St. Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia: A Six Year Retrospective Case‒Control Study, 2024","fulltext":[{"header":"1. Introduction","content":"\u003cdiv id=\"Sec2\" class=\"Section2\"\u003e \u003ch2\u003e1.1. Background\u003c/h2\u003e \u003cp\u003eLung cancer is one of the most lethal malignancies, worldwide and is responsible for more deaths than any other cancer type. According to the Global Cancer Observatory, it accounts for approximately 11.6% of all cancer diagnoses and 18.4% of cancer-related deaths worldwide [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The disease is characterized by its aggressive nature, rapid progression, and poor prognosis, especially when it is diagnosed at advanced stages. While historically associated with high-income countries due to industrial exposure and tobacco use, recent trends show a rising incidence in low- and middle-income nations, including Ethiopia [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eLung cancer is the most commonly diagnosed cancer worldwide, with over 2\u0026nbsp;million new cases annually [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. It is broadly classified into non-small_cell lung cancer (NSCLC) and small_cell lung cancer (SCLC). NSCLC accounts for approximately 85% of cases and includes adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. SCLC, although less common, is more aggressive and often presents with early metastasis [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Adenocarcinoma has become the most prevalent subtype globally, particularly among nonsmokers and women. This shift is attributed to changes in smoking habits, increased exposure to environmental pollutants, and improved diagnostic techniques [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTobacco smoking remains the leading risk factor for lung cancer and is responsible for nearly 85% of cases [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The risk increases with the duration and intensity of smoking. Passive smoking also contributes significantly, especially among women and children. In many low-income countries, biomass fuels (wood, charcoal, and dung) are used for cooking and heating. Prolonged exposure to smoke from these sources has been linked to chronic respiratory diseases and lung cancer [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Women are disproportionately affected by their domestic roles.\u003c/p\u003e \u003cp\u003eExposure to carcinogens such as asbestos, silica, radon, and diesel exhaust increases the risk of lung cancer. Urban air pollution, particularly fine particulate matter (PM2.5), has also been implicated [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Although less common, genetic predisposition plays a role in lung cancer development. Mutations in genes such as EGFR, ALK, and KRAS are associated with specific subtypes and influence treatment response [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eStudies from African countries have shown variability in histologic subtypes. In Egypt and Nigeria, adenocarcinoma is the most common type, followed by squamous cell carcinoma [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Late-stage presentation is common due to limited access to healthcare and diagnostic services.\u003c/p\u003e \u003cp\u003eA study at Tikur Anbessa Specialized Hospital (TASH) reported adenocarcinoma as the dominant subtype, with most cases being diagnosed at stage IV [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Another study using machine learning identified coughing blood, air pollution, and obesity as predictive features for lung cancer [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. However, these studies lacked control groups and comprehensive risk factor analysis.\u003c/p\u003e \u003cp\u003eIn Ethiopia, the use of biomass fuels for cooking and heating, limited access to healthcare, and increasing tobacco consumption contribute to the increasing burden of lung cancer. Despite this, lung cancer remains underdiagnosed and underreported due to the lack of national cancer registries, inadequate diagnostic infrastructure, and low public awareness. Histopathologic evaluation remains the cornerstone of diagnosis, yet access to biopsy and pathology services is limited to a few tertiary institutions.\u003c/p\u003e \u003cp\u003eSPHMMC is one of the few centers in Ethiopia with consistent histopathologic reporting and electronic medical records. This study leverages data from SPHMMC to explore the determinants and histopathological patterns of lung cancer, aiming to fill a critical gap in local cancer epidemiology.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e1.2. Statement of the Problem\u003c/h2\u003e \u003cp\u003eDespite the increasing burden of lung cancer in Ethiopia, there is a significant lack of localized data on its epidemiology, histopathologic subtypes, and associated risk factors. Most existing studies are descriptive, single-center reports that do not employ robust analytical designs. As a result, public health interventions remain generic and poorly targeted.\u003c/p\u003e \u003cp\u003ePatients often present at advanced stages due to delayed diagnosis, misinterpretation of symptoms, and limited access to imaging and pathology services. Moreover, the contributions of environmental and lifestyle factors such as biomass fuel exposure, smoking, and occupational hazards remain poorly understood in the Ethiopian context. Without evidence-based insights, clinicians face challenges in early detection, risk stratification, and treatment planning.\u003c/p\u003e \u003cp\u003eThis study addresses these gaps by analyzing lung cancer cases diagnosed at SPHMMC over a six-year period, using a case‒control design to identify key determinants and describe histopathological patterns. The findings aim to inform clinical practice and guide public health policy.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e1.3. Rationale of the Study\u003c/h2\u003e \u003cp\u003eUnderstanding the determinants and histopathological characteristics of lung cancer in Ethiopia is essential for several reasons. First, it enables the identification of high-risk populations, particularly those exposed to tobacco smoke and biomass fuels. Second, it provides insights into the most prevalent histologic subtypes, which can guide diagnostic protocols and treatment decisions. Third, it highlights systemic barriers to early diagnosis, such as limited access to imaging and pathology services.\u003c/p\u003e \u003cp\u003eBy generating evidence from a tertiary care center with reliable pathology data, this study contributes to the national discourse on cancer control. It supports the development of targeted awareness campaigns, resource allocation for diagnostic infrastructure, and the integration of lung cancer screening into primary healthcare. Furthermore, the findings can serve as a baseline for future multicenter studies and inform the creation of a national cancer registry.\u003c/p\u003e \u003c/div\u003e"},{"header":"2. Methods and Materials","content":"\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Study Area and Period\u003c/h2\u003e \u003cp\u003eThe study was conducted at SPHMMC, which is located on Swaziland Street in Addis Ababa, Ethiopia. Established by a Council of Ministers resolution in 2010, the hospital and medical school traced their origins to 1969, were founded by Emperor Haile Selassie, and officially opened in 2007. Serving more than 5\u0026nbsp;million people, the SPHMMC provides comprehensive inpatient and outpatient care across various specialties. Its Pathology Center has been operational since 2014 and, is among the few advanced facilities in the country, archiving specimens from multiple institutions. It delivers fine-needle aspiration cytology (FNAC) services to more than 7,000 patients annually and performs approximately 6,000 biopsies each year. The study period extended from January 2, 2024 to January 1, 2025. This duration was selected to accommodate the low incidence of lung cancer within the institution and to ensure sufficient time for excluding malignancies in the control group.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Study Design\u003c/h2\u003e \u003cp\u003eA hospital-based case‒control study design was employed.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Source population\u003c/h2\u003e \u003cp\u003eThe source population included all patients who had lung biopsy samples submitted to the pathology department of SPHMMC between September 2018 and January 2024.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e2.4. Study Population with Eligibility Criteria\u003c/h2\u003e \u003cp\u003eThe study population included patients who underwent lung biopsy at SPHMMC between September 2018 and January 2024, with complete histopathologic and clinical records.\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eInclusion criteria\u003c/b\u003e:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003ePatients with histopathologically confirmed lung cancer (cases)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003ePatients with nonmalignant lung biopsy results (controls)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eAvailability of complete demographic and clinical data\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eExclusion criteria\u003c/b\u003e:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003ePatients with equivocal or inconclusive biopsy results\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eIncomplete pathology reports or missing key clinical information\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e2.5. Sample size determination\u003c/h2\u003e \u003cp\u003eThe sample size was calculated via a double population proportion formula, assuming a 95% confidence level, 80% power, and a 1:2 case-to-control ratio. On the basis of previous studies indicating a smoking prevalence among lung cancer patients of approximately 60% and among controls of 20%, the minimum required sample size was 105 (35 cases and 70 controls). This was adjusted for feasibility and availability of complete records.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e2.6. Sampling Technique\u003c/h2\u003e \u003cp\u003eCases were selected consecutively from histopathologically confirmed lung cancer patients. Controls were selected via simple random sampling from eligible noncancer patients who underwent lung biopsy during the same period.\u003c/p\u003e \u003cp\u003e \u003cb\u003e2.6. Operational definitions\u003c/b\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003e\u0026bull; Case\u003c/strong\u003e \u003cp\u003e\u0026bull; A patient with histopathologically confirmed lung cancer diagnosis.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eControl\u003c/b\u003e: A patient with nonmalignant lung biopsy findings.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eBiomass Fuel Exposure\u003c/b\u003e: Use of wood, charcoal, dung, or crop residues for cooking or heating.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eSmoking history\u003c/b\u003e: Self-reported history of tobacco use, including cigarettes or traditional forms.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eLung cancer\u003c/b\u003e: histopathologically confirmed cases of primary lung cancer at the SPHMMC pathology department\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e2.7. Variables\u003c/h2\u003e \u003cp\u003e \u003cb\u003eDependent Variable\u003c/b\u003e:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eHistopathologically confirmed lung cancer diagnosis\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eIndependent Variables\u003c/b\u003e:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eSex\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eResidence\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eSmoking history\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eBiomass fuel exposure\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eFamily history of cancer\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eOccupational exposure\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eClinical symptoms\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eRadiologic findings\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eTumor location\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eCancer stage\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eHistopathologic subtypes\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003e2.8. Data collection procedure\u003c/h2\u003e \u003cp\u003eData were collected retrospectively from electronic pathology records and patient charts. A structured checklist was used to extract relevant variables. Histopathologic reports were reviewed by certified pathologists, and clinical data were verified through chart abstraction.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003e2.9. Data Processing and Analysis\u003c/h2\u003e \u003cp\u003eThe data were entered into SPSS version 26 for analysis. Descriptive statistics were used to summarize demographic and clinical characteristics. Fisher\u0026rsquo;s exact test was applied to assess associations between categorical variables due to the small sample size. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to identify significant determinants of lung cancer.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003e2.10. Data Quality Assurance\u003c/h2\u003e \u003cp\u003eTo ensure data quality, the checklist was pretested on a small sample before full data collection. Double data entry was performed to minimize errors. Histopathologic diagnoses were cross-checked by two independent pathologists. Incomplete records were excluded from analysis.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003e2.11. Ethical considerations\u003c/h2\u003e \u003cp\u003eEthical clearance for this study was obtained from IRBs of Y12HMC and SPHMMC. Because the study was retrospective in nature, and relied exclusively on anonymized patient records without direct involvement of human subjects, the IRBs formally waived the requirement for individual informed consent. Confidentiality and anonymity were rigorously maintained throughout the data collection, with no personally identifiable information recorded or disclosed, ensuring that dissemination of the findings adheres to established ethical standards.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003e2.12. Dissemination Plan\u003c/h2\u003e \u003cp\u003eThe findings of this study were disseminated to SPHMMC, the Ethiopian Ministry of Health, and relevant stakeholders through presentations. After publication, copies will also be made available to academic institutions and libraries for reference.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec19\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Sociodemographic characteristics\u003c/h2\u003e \u003cp\u003eA total of 105 patients were included in the study, comprising 35 histopathologically confirmed lung cancer patients and 70 controls. The mean age of all participants was 43.83 years (SD\u0026thinsp;\u0026plusmn;\u0026thinsp;14.2), with the average age of the lung cancer patients being 45.2 years. The age distribution revealed that the majority of cases (54.3%) fell within the 41\u0026ndash; 60 years age group, followed by 28.6% in the 21\u0026ndash; 40 years age range. Only 17.1% of the patients were above 60 years of age, indicating a relatively younger cohort than the global trend.\u003c/p\u003e \u003cp\u003eThe gender distribution showed a nearly equal split, with a male-to-female ratio of 1.1:1 overall. Among lung cancer cases, females slightly outnumbered males (M:F ratio 0.94:1), which contrasts with global data that typically show male predominance.\u003c/p\u003e \u003cp\u003eResidency data were incomplete, with 39.1% missing. Among the available data, 27.6% of the participants were urban dwellers, and 33.3% were rural residents.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eInsert Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e here\u003c/strong\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSociodemographic Characteristics of Lung Cancer Patients at SPHMMC, Addis Ababa Ethiopia, September 2018 to January 2024.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCategories\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eCase/Control\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eLung Ca\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eNon-Lung Ca\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003eTotal\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u0026ndash;25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1(2.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17(24.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e18(17.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25\u0026ndash;50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13(37.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30(42.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e43 (41.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50\u0026ndash;75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17(48.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23(32.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e40(38.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e75\u0026ndash;100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(11.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4(3.8%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17(48.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e38(54.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e55(52.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18(51.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32(45.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e50 (47.6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eResidency area\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eUrban\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10(28.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19(27.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29(27.6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRural\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11(31.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24(34.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e35(33.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMissing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14(40.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27(38.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e41(39.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eSociodemographic characteristics of lung cancer patients at SPHMMC, Addis Ababa Ethiopia, from September 2018 to January 2024.\u003c/p\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section2\"\u003e \u003ch2\u003e3.2. Clinical presentation\u003c/h2\u003e \u003cp\u003eThe most frequently reported symptoms among lung cancer patients were chronic cough (81%), dyspnea (68.6%), chest pain (59%), and weight loss (80%). Fever was noted in 34.3% of the patients, whereas hemoptysis occurred in 22.9%. These symptoms are consistent with advanced pulmonary disease and often overlap with other respiratory conditions, contributing to diagnostic delays.\u003c/p\u003e \u003cp\u003eRadiologic findings revealed mass lesions in 67.6% of the patients, followed by consolidation (15%), cavitation (10%), and pleural effusion (7.4%). These findings are often nonspecific and require histopathological confirmation.\u003c/p\u003e \u003cp\u003eAmong the 18 patients with documented stage disease, 61.1% were diagnosed with stage IV disease, 22.2% with stage III disease, and 16.7% with stage II disease. No patients were diagnosed with stage I disease. Metastasis was present in 50% of the patients, with the contralateral lung and liver being the most common sites.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eInsert Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e here\u003c/strong\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eClinical Features of Lung Cancer Patients at SPHMMC, Addis Ababa, Ethiopia, September 2018 to January 2024.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eCase/Control\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eLung Ca\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eNon-Lung Ca\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003eTotal\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eHospitalization status\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11(31.40%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e40(57.10%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e51(48.60%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24(68.60%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30(42.90%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e54(51.40%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eCough\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e34(97.10%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e51(72.90%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e85(81%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1(2.90%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19(27.10%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e20(19%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eShortness of Breath\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31(88.60%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e41(58.60%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e72(68.60%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(11.40%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e29(41.40%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e33(31.40%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eChest pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21(60%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e41(58.60%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e62(59%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14(40%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e29(41.40%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e43 (41%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eHemoptysis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15(42.90%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12(17.10%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e27(25.70%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20(57.10%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e58(82.90%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e78(74.30%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eWeight Loss\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28(80%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e26(37.10%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e54(51.40%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7(20%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e44(62.90%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e51(48.60%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eFever\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12(34.30%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19(27.10%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e31(29.50%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23(65.70%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e51(72.90%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e74(70.50%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"4\" rowspan=\"5\"\u003e \u003cp\u003eMethod of Biopsy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBronchoscopy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6(17.10%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7(10%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e13(12.40%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLobectomy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6(17.10%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15(21.40%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e21(20%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCNB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22(62.90%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23(32.90%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e45(42.90%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eResection\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1(2.90%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11(15.70%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12(11.40%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eThoracotomy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14(20%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e14(13.30%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eOrientation of Tumor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23(65.70%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e37(52.90%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e60(57.10%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLeft\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9(25.70%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30(42.90%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e39(37.10%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBilateral\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3(8.60%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3(4.30%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6(5.70%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eClinical features of lung cancer patients at SPHMMC, Addis Ababa, Ethiopia, from September 2018 to January 2024.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eInsert Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e here\u003c/strong\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eRadiologic findings of lung cancer patients at SPHMMC, Addis Ababa, Ethiopia, from September 2018 to January 2024.\u003c/p\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec21\" class=\"Section2\"\u003e \u003ch2\u003e3.3. Histopathologic patterns\u003c/h2\u003e \u003cp\u003eHistopathologic analysis revealed that adenocarcinoma was the most prevalent subtype, accounting for 46% of cases. Squamous cell carcinoma and small cell carcinoma each represented 11% of the cases. Other subtypes included poorly differentiated carcinoma (9%), large cell carcinoma (6%), and rare variants such as carcinoid tumors.\u003c/p\u003e \u003cp\u003eTumor location analysis revealed that 57.1% of cases involved the right lung, with the upper lobe being the most frequently affected site. This distribution may be influenced by anatomical and airflow dynamics, although further investigation is needed.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eInsert Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e here\u003c/strong\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eHistopathologic patterns of the case group in the assessment of lung cancer at SPHMMC, Addis Ababa, Ethiopia, from September 2018 to January 2024.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eInsert Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e here\u003c/strong\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eHistopathologic patterns of the control group in the assessment of lung cancer SPHMMC, Addis Ababa, Ethiopia, from September 2018 to January 2024.\u003c/p\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec22\" class=\"Section2\"\u003e \u003ch2\u003e3.4. Determinants of Lung Cancer\u003c/h2\u003e \u003cp\u003eSmoking was reported by 57.1% of the lung cancer patients, whereas only 5.7% of the controls smoked. This yielded an odds ratio (OR) of 4.5 (95% CI: 2.1\u0026ndash;9.8, p\u0026thinsp;=\u0026thinsp;0.001), confirming a strong association between tobacco use and lung cancer.\u003c/p\u003e \u003cp\u003eBiomass fuel exposure was reported by 40% of the cases and 20% of the controls, resulting in an OR of 2.2 (95% CI: 1.01\u0026ndash;4.8, p\u0026thinsp;=\u0026thinsp;0.048). No participants reported a family history of lung cancer. Occupational exposure data were incomplete and excluded from analysis.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eInsert Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e here\u003c/strong\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eFisher\u0026rsquo;s Exact Test Analysis of Determinant Factors for Lung Cancer at SPHMMC, Addis Ababa, Ethiopia, September 2018 to January 2024.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003eLung Ca\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFisher's Exact p-value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eUnadjusted OR (95%CI)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17(48.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e38(54.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.679\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.85(0.5,1.47)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18(51.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32(45.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSmoking\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20(57.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4(5.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.50(2.75,7.350)**\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15(42.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e66(94.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eBiomass use\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14(40%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14(20%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.048\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.20(1.293,5.173)**\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5(14.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17(24.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eAge Category\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;=50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14(40%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e47(67.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.078\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.481(0.276,1.837)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21(60%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e23(32.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eResidency\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eUrban\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10(28.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19(27.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.09(0.54,2.21)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRural\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11(31.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24(34.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eHistory of Alcoholism\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6(17.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10(14.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.15(0.57,2.317)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e29(82.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e60(85.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003e**Significant association at p-value of less than 0.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eFisher\u0026rsquo;s exact test analysis of determinant factors for lung cancer at SPHMMC, Addis Ababa, Ethiopia, from September 2018 to January 2024.\u003c/p\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eGlobally, lung cancer remains the most frequently diagnosed cancer and the leading cause of cancer-related death, accounting for 2.1\u0026nbsp;million new cases and 1.8\u0026nbsp;million deaths annually [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Although lung cancer ranks lower in incidence than other cancers do in Ethiopia, its mortality burden is significant. The Addis Ababa cancer registry places lung carcinoma as the sixth most common malignancy among males [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The findings of this study reveal a distinct epidemiologic profile of lung cancer at SPHMMC, with patients presenting at a younger age (mean 45.2 years) compared with studies in Bangladesh (mean 59.57 years) [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] and TASH (median 54 years) [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. This younger age distribution may reflect earlier exposure to risk factors or diagnostic delays due to limited healthcare access.\u003c/p\u003e \u003cp\u003eThe gender distribution in this study shows near parity (M:F ratio 0.94:1), which contrasts with global trends where males are disproportionately affected [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. This may be attributed to environmental exposures such as biomass fuel use, which is more common among women in Ethiopia. The residency data revealed a slight rural predominance among the cases, suggesting a possible link to indoor air pollution and limited access to early diagnostic services.\u003c/p\u003e \u003cp\u003eClinically, the most common symptoms were cough (97.1%), shortness of breath (88.6%), and chest pain (60%), which is consistent with findings from studies in Egypt [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], India [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], and TASH [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The average symptom duration was 7.9 months, indicating delayed presentation. Notably, 14.3% of the patients were initially treated for tuberculosis, highlighting the diagnostic overlap between TB and lung cancer. Metastasis was present in 37% of the patients, with distant spread in 61.5%, primarily to the contralateral lung and liver. Stage IV disease was documented in 31.4% of the patient, which was lower than the 76.2% reported in TASH [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] but still indicative of late-stage disease.\u003c/p\u003e \u003cp\u003eRadiologic findings were dominated by mass lesions (82.9%), followed by consolidation and combined presentations. The tumors were more frequently located in the right lung (57.1%), which aligns with the anatomical predispositions noted in other studies [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Histopathologically, adenocarcinoma was the most prevalent subtype (46%), followed by squamous cell carcinoma and small cell lung cancer (each 11%). This pattern mirrors global shifts toward adenocarcinoma dominance, especially among nonsmokers and women [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Compared with older studies from Turkey [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e], Iran [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], and South Africa [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] where squamous cell carcinoma was more common, the current trend reflects changing environmental exposures and diagnostic practices.\u003c/p\u003e \u003cp\u003eSmoking was strongly associated with lung cancer in this study, with an odds ratio of 4.5. This aligns with international findings and reinforces tobacco use as the primary risk factor [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. The smoking prevalence among cases (57.1%) is higher than national estimates but comparable to rates reported in Turkey [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] and Iran [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Biomass fuel use also showed a significant association (OR\u0026thinsp;=\u0026thinsp;2.2), underscoring its role as a local environmental risk factor. This finding is particularly relevant in Ethiopia, where traditional cooking methods are widespread [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. The absence of reported family history and incomplete occupational exposure data limit conclusions about genetic and workplace-related risks.\u003c/p\u003e"},{"header":"5. Strengths and Limitations","content":"\u003cp\u003eThis study is the first of its kind in Ethiopia to employ a case‒control design for investigating lung cancer determinants. It provides a comprehensive analysis of histopathological patterns and risk factors, contributing to the limited body of local evidence.\u003c/p\u003e \u003cp\u003eHowever, several limitations must be acknowledged. The small sample size reduces the statistical power and limits generalizability. Missing data on residency, occupation, and staging hindered deeper analysis. The retrospective design is subject to information bias, and reliance on chart reviews may have led to underreporting of exposures.\u003c/p\u003e \u003cp\u003eDespite these limitations, the study offers important insights and lays the groundwork for future research.\u003c/p\u003e"},{"header":"6. Conclusion","content":"\u003cp\u003eThis study highlights the distinctive profile of lung cancer at SPHMMC, Ethiopia, which is characterized by a younger patient demographic (mean age: 45.2 years) and near-gender parity (male‑to‑female ratio: 0.94:1), diverging from global trends. In this relatively low‑smoking population, biomass fuel use (OR\u0026thinsp;=\u0026thinsp;2.2) emerged as a significant risk factor, whereas smoking (OR\u0026thinsp;=\u0026thinsp;4.5) remained the predominant determinant. Adenocarcinoma was the major histologic type (46%), which is consistent with the increasing global incidence among nonsmokers. The high proportion of late‑stage diagnoses (61.1% stage IV) underscores systemic delays in detection and access to care. These findings reinforce the urgent need for earlier diagnostic pathways, investment in cleaner energy initiatives to reduce indoor air pollution, and targeted smoking cessation programs.\u003c/p\u003e"},{"header":"Abbreviations","content":" \u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCCC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCoordinated and Comprehensive Cancer Care\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCIs\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003econfidence intervals\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDALY\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eDisability Adjusted Life Years\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEFMOH\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEthiopian Federal Ministry of Health\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEGFR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEpidermal growth factor receptor\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFNAC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eFine needle aspiration cytology\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGLOBCON\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eGlobal Cancer Observatory\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIRB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInstitutional Review Board\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eNSCLC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eNon-Small Cell Lung Cancer\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eOdds ratio\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSCC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSquamous cell carcinoma\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSCLC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSmall cell lung cancer\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eStandard deviation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSPHMMC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSt. Paul's Hospital Millennium Medical College\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSPSS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eStatistical Package for Social Sciences\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTASH\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTikure Anbesa Specialized Hospital\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eUSA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eUnited States of America\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eWHO\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eWorld Health Organization\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eWSE\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eWood Smoke Exposure\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eY12HMC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eYekatit 12 Hospital Medical College\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthical Approval and Consent to Participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthical clearance for this study was obtained from the IRBs of Y12HMC and SPHMMC. Because the study was retrospective in nature, and relied exclusively on anonymized patient records without direct involvement of human subjects, the IRBs formally waived the requirement for individual informed consent. Confidentiality and anonymity were rigorously maintained throughout the data collection, with no personally identifiable information recorded or disclosed, ensuring that dissemination of the findings adheres to established ethical standards.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for Publication:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of Data and Materials:\u0026nbsp;\u003c/strong\u003eThe corresponding author will make the research data and supporting materials available upon reasonable request from the editorial team.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests:\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no conflicts of interest. The sole interest is academic dissemination through publication.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDr Amanuel Yeneneh Teka: conceptualization, methodology, writing original draft, data curation, formal analysis, investigation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDr Bacha Mirkena Dhabi: Writing review and editing, writing manuscript, data collection and data entry, formal analysis\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDr Tsigehana Sisay Mekonnen: Writing original draft, data collection, data entry, formal analysis\u003c/p\u003e\n\u003cp\u003eYimer Seid Yimer: Supervision, Project administration, Validation\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFirst and foremost, we express our deepest gratitude to God for granting us the strength and perseverance to complete this research\u0026mdash;from proposal development to final analysis. We extend our sincere appreciation to Y12HMC and its Department of Public Health for facilitating this academic opportunity. We are also profoundly grateful to SPHMMC for granting access to patient records and supporting the implementation of this study in their facility.\u003c/p\u003e\n\u003cp\u003eWe would like to acknowledge the Pathology Department of SPHMMC for their invaluable collaboration. Our heartfelt appreciation is also extended to the Patient Record Keeping Unit of SPHMMC for their assistance in data retrieval and documentation.\u003c/p\u003e\n\u003cp\u003eWe further extend our appreciation to Mr. Mohammed Abdu Yimam, a cyber security expert, for his technical guidance and support in ensuring data protection throughout the study.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWhat Is Cancer? [Internet]. National Cancer Institute. Cancer.gov. 2021. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.cancer.gov/about-cancer/understanding/what-is-cancer\u003c/span\u003e\u003cspan address=\"https://www.cancer.gov/about-cancer/understanding/what-is-cancer\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA: A Cancer Journal for Clinicians. 2021; 71(3):209\u0026thinsp;\u0026ndash;\u0026thinsp;49.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAwedew AF, Asefa Z, Belay WB. National Burden and Trend of Cancer in Ethiopia, 2010 2019: a systemic analysis for Global burden of disease study. Sci Rep. 2022;12 (1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUpToDate.Uptodate.com. 2023.Available from:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.uptodate.com/contents/overview-of-the-initial-treatment-and\u003c/span\u003e\u003cspan address=\"https://www.uptodate.com/contents/overview-of-the-initial-treatment-and\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e prognosis-of lung-cancer?source\u0026thinsp;=\u0026thinsp;bookmarks_widget.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSiegel RL, Miller KD, Fuchs HE, Jemal A, Cancer Statistics. 2021. CA: A Cancer Journal for Clinicians. 2021; 71(1):7\u0026ndash;33.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarta JA, Powell CA, Wisnivesky JP. Global Epidemiology of Lung Cancer. Annals Global Health. 2019; 85 (1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eArticle R, Tigeneh W, Molla A, Abreha A, Assefa M, Citation: Tigeneh W. (2015) Pattern of Cancer in Tikur Anbessa Specialized Hospital Oncology Center in Ethiopia from 1998 to 2010. Int J Cancer Res Mol Mech. 2015; 1(1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMuir CS, Waterhouse J, Mack TM, Powell J, Whelan S, editors. Cancer Incidence in Five Continents. Vol, X. Lyon, France: International Agency for Research on Cancer.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrevalence | Tobacco Atlas [Internet]. Tobacco Atlas. 2022 [cited 2023 Jan 15]. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://tobaccoatlas.org/challenges/prevalence/\u003c/span\u003e\u003cspan address=\"https://tobaccoatlas.org/challenges/prevalence/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMengesha SD, Teklu KT, Weldetinsae A, Serte MG, Kenea MA, Dinssa DA et al. Tobacco use prevalence and its determinate factor in Ethiopia- finding of the 2016 Ethiopian GATS. BMC Public Health. 2022; 22(1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUpToDate [Internet]. Uptodate.com. 2023 [cited 2023 Jan 15]. Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.uptodate.com/contents/cigarette-smoking-and-other-possible-risk-factors for-lung-cancer/abstract/35\u0026ndash;44\u003c/span\u003e\u003cspan address=\"https://www.uptodate.com/contents/cigarette-smoking-and-other-possible-risk-factors for-lung-cancer/abstract/35\u0026ndash;44\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBoloker G, Wang C, Zhang J. Updated statistics of lung and bronchus cancer in United States (2018). J Thorac Disease. 2018;10(3):1158\u0026ndash;61.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHosseini M, Naghan PA, Karimi S, SeyedAlinaghi S, Bahadori M, Khodadad K, et al. Environmental risk factors for lung cancer in Iran: a case-control study. Int J Epidemiol. 2009;38(4):989\u0026ndash;96.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGanesh. A case\u0026ndash;control study of risk factors for lung cancer in Mumbai, India. Asian Pac J cancer prevention: APJCP. 2024; 12(2).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHouston K, Henley S, Li J, White M, Richards T. Lung Cancer. HHS Public Access. 2014;86(1):22\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuarga L, Ameijide A, Marcos-Gragera R, Carulla M, Delgadillo J, Borr\u0026agrave;s JM et al. Trends in lung cancer incidence by age, sex and histology from 2012 to 2025 in Catalonia (Spain). Sci Rep. 2021; 11(1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDemirci E, Daloglu F, Gundogdu C, Calik M, Sipal S, Akgun M. Incidence and Clinicopathologic Features of Primary Lung Cancer: A North-Eastern Anatolia Region Study in Turkey (2006\u0026ndash;2012). Asian Pac J Cancer Prev. 2013;14(3):1989\u0026ndash;93.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUgur Gonlugur TE, Gonlugur M, Kaptanoglu, Cinar Z. The changing epidemiological trends for carcinoma of the lung in Turkey. Saudi Med J. 2008;29(5):749\u0026ndash;53.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGupta R, Chowdhary I, Singh PORIGINALARTICLE, Clinical. Radiological and Histological profile of Primary Lung Carcinomas. JK SCIENCE 146 www.kscience.org. 2015; 17(3).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChakrabortty R, Siddiqua DR, Paul SK, Rahman S, Biswas SK. Histopathological Patterns of Lung Cancer along with Clinico-Radiological Correlation in a Tertiary Care Hospital in Bangladesh. J Med. 2022;23(2):126\u0026ndash;31.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHajmanoochehri F, Mohammadi N, Zohal MA, Sodagar A, Ebtehaj M. Epidemiological and Clinicopathological Characteristics of Lung Cancer in a Teaching Hospital in Iran. Asian Pac J Cancer Prev. 2014;15(6):2495\u0026ndash;500.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAkl YM, Emam RH, Sabry IM, Ali AA. Clinico-pathological profile of bronchogenic carcinoma cases presented to Chest Department, Cairo University in the last 10 years. Egypt J Chest Dis Tuberculosis. 2013;62(4):705\u0026ndash;12.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJohannesburg S. Africa. Southern African Journal of Infectious Diseases A Study of lung cancer in Johannesburg, South Africa.Southern African. J Infect Dis. 2015;29(1):43\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMissaoui N, Hmissa S, Landolsi H, Korbi S, Joma W, Anjorin A, Ben Abdelkrim S. Beizig N;Mokni M. Lung cancer in central Tunisia: epidemiology and clinicopathological features. Asian Pac J cancer prevention: APJCP.2016; 12(9).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZakkouri FA, Saloua O, Halima A, Rachid R, Hind M, Hassan E. Smoking, passive smoking and lung cancer cell types among women in Morocco: analysis of epidemiological profiling of 101 cases. BMC Res Notes. 2015; 8(1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi D, Shi J, Liang D, Ren M, He Y. Lung cancer risk and exposure to air pollution: a multicenter North China case\u0026ndash;control study involving 14604 subjects. BMC Pulm Med. 2023; 23(1).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pulmonary-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pulm","sideBox":"Learn more about [BMC Pulmonary Medicine](http://bmcpulmmed.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pulm/default.aspx","title":"BMC Pulmonary Medicine","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"biomass use, lung cancer, histopathology, retrospective analysis, smoking prevalence, Ethiopia","lastPublishedDoi":"10.21203/rs.3.rs-8089607/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8089607/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eLung cancer is the leading cause of cancer-related death globally, accounting for 1.8\u0026nbsp;million deaths annually. Its incidence is increasing in low- and middle-income countries (LMICs), including Ethiopia, where it comprises 1.5% of all cancers. Despite this, lung cancer remains locally underresearched.\u003c/p\u003e\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eTo assess the determining factors and histopathological patterns of lung cancer at St. Paul\u0026rsquo;s Hospital Millennium Medical College (SPHMMC), Addis Ababa, Ethiopia.\u003c/p\u003e\u003ch2\u003eMethod\u003c/h2\u003e \u003cp\u003eA hospital-based case‒control study involving 105 participants (35 cases and 70 controls) selected from histopathology-confirmed lung biopsies was conducted from January 2024 to January 2025. The Data were cleaned via EPI Data and analyzed via SPSS version-26. Descriptive statistics were used to summarize the findings, and Fisher\u0026rsquo;s exact test with odds ratios was used to identify determinants, as the sample size was insufficient for logistic regression modeling.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe mean age was 43.83 years, with near-gender parity (M:F ratio of 1.1:1); there was a slight female predominance (0.94:1). Most patients (61.1%) were diagnosed with stage IV disease. Common symptoms included cough (81.0%), dyspnea (68.6%), and chest pain (59.0%). Radiologic findings revealed mass lesions in 67.6% of the patients. Adenocarcinoma was the predominant histologic subtype (46%). Smoking (OR\u0026thinsp;=\u0026thinsp;4.50, p\u0026thinsp;=\u0026thinsp;0.001) and biomass fuel use (OR\u0026thinsp;=\u0026thinsp;2.20, p\u0026thinsp;=\u0026thinsp;0.048) were significant risk factors.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eLung cancer at SPHMMC affects relatively young patients with near gender parity. Late-stage presentation and strong associations with smoking and biomass exposure highlight the need for early detection, smoking cessation, and clean energy initiatives.\u003c/p\u003e","manuscriptTitle":"Determinants and Histopathologic Patterns of Lung Cancer at St. Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia: A Six Year Retrospective Case‒Control Study, 2024","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-22 09:00:47","doi":"10.21203/rs.3.rs-8089607/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-31T05:38:28+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-14T20:01:53+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"3096597192028352425211343630390946446","date":"2026-03-13T18:23:22+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-22T14:35:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"170344430762422467600762207321114577560","date":"2025-12-22T04:37:16+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-19T18:02:48+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"338513511062720264573729580374870133362","date":"2025-12-19T16:48:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"25362616896714408000084272691563783766","date":"2025-12-19T16:28:36+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-12-12T07:29:54+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-12-08T15:25:15+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-11-19T07:52:13+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-11-18T21:05:21+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pulmonary Medicine","date":"2025-11-18T21:02:37+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pulmonary-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"pulm","sideBox":"Learn more about [BMC Pulmonary Medicine](http://bmcpulmmed.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/pulm/default.aspx","title":"BMC Pulmonary Medicine","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"38c63251-5ab0-4efb-b52a-65f823b2d895","owner":[],"postedDate":"December 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[],"tags":[],"updatedAt":"2026-03-31T05:54:31+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-22 09:00:47","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8089607","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8089607","identity":"rs-8089607","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}