Treatment patterns and survival outcomes of Ewing sarcoma in Ethiopia: A five-year retrospective analysis from a tertiary hospital

Treatment patterns and survival outcomes of Ewing sarcoma in Ethiopia: A five-year retrospective analysis from a tertiary hospital | 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 Treatment patterns and survival outcomes of Ewing sarcoma in Ethiopia: A five-year retrospective analysis from a tertiary hospital Tegene Gizaw, Adugna Fikadu, Gashaw Arega, Birhanu Tesfaye, Damena Teshome, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9021771/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 14 You are reading this latest preprint version Abstract Background : Ewing sarcoma is a malignant small round-cell sarcoma of bone or soft tissue that is highly responsive to modern multimodal therapy and considered as highly curable disease developed countries. However, survival remains poor in developing countries.This study aims to assess treatment patterns and survival outcomes of Ewing sarcoma at Tikur Anbessa Hospital. Methods and Materials : we conducted a retrospective study on all patient diagnosed with Ewing sarcoma at Tikur Anbessa Hospital between November 15, 2018, and November 15, 2023. Descriptive statistics and Kaplan-Meier survival analysis were used to analyze the data. Result : The median age at diagnosis was 19 years, with most of the patients (67.2%) in the age range of 8-25 year. The main modality of treatment for localized disease was chemotherapy combined with surgery, whereas chemotherapy alone was used for metastatic disease. The 3-year overall survival (OS) and event-free survival (EFS) for entire cohort were 68%% and 40%, respectively. The 3-year OS and EFS rates were 89% and 76% for localized disease versus 10% and 0% for metastatic disease.This diffrence for both OS and EFS reaching statistical significance (log-rank p < 0.001). Small tumor size (≤ 8 cm), surgical intervention and localized stage were associated with statistically significant improvement in OS and EFS, whereas pelvic location was poorer prognosis. Conclusion : Ewing sarcoma at our institution mainly affects adolescents and young adults. Survival is poor, especially for metastatic disease, while localized tumors, smaller size, and surgery are associated with better survival. Theirfor early diagnosis and improved multimodal treatment are needed to improve survival. Ewing sarcoma bone tumor treatment pattern survival TASH Ethiopia Figures Figure 1 Figure 2 Introduction Ewing sarcoma (ES) is a malignant small round-cell tumor of bone or soft tissue characterized by rearrangements of Ewing Sarcoma RNA binding protein 1 (EWSR1) gene and members of the E26 transformation-specific (ETS) transcription factor family [ 1 – 3 ]. It is the third most common primary bone malignancy overall and the second most common primary bone malignancy in pediatrics and adolescents group, comprising approximately 2–3% of all malignancies in this age group. Although its incidence is unknown in older populations, approximately 30% of cases occur in individuals older than 20 years [ 4 – 8 ]. Unlike most other bone and soft tissue sarcomas, ES is highly sensitivity to both systemic multiagent chemotherapy and radiotherapy. Over the past few decades, data from developed countries have shown that, the 5-year survival rate has improved from 10% to over 70% for localized disease and from 0% to 30% for metastatic disease [ 8 – 12 ]. However data on treatment patterns and survival outcome from low- and middle-income countries are limited. Available reports suggest that 5-year survival for localized disease ranges from 35–69%, and about 4% for metastatic disease. To best of our knowledge, no published data exist on survival and treatment modality Ewing sarcoma from Sub-Saharan Africa including Ethiopia [ 13 , 14 ]. Therefore the aim of this study is to evaluate the treatment patterns and survival outcome of patients with Ewing sarcoma at Tikur Anbessa Hospital, Ethiopia. The finding will provide locally relevant evidence to inform clinical decision-making and optimize resources allocation, while also establishing a foundation for future prospective research in resource-limited settings. Methods Study design and setting This retrospective cohort study was conducted at Tikur Anbessa Specialized Hospital (TASH), Addis Ababa University, Ethiopia’s which is largest tertiary referral center and the country’s leading facility for comprehensive cancer care, including chemotherapy, radiotherapy, surgery, and palliative services.The study was performed in the adult oncology department and Pediatric Hematology–Oncology Unit. Study population, sample size and eligibility criteria Due to small total number of population under investigation (n = 61), all consecutive pediatric and adult patients diagnosed with Ewing sarcoma and treated at Tikur Anbessa Specialized Hospital during the 5-year period (November 15, 2018, to November 15, 2023) who met the inclusion and exclusion criteria were included. Patients were excluded if they had missing data on key variables to estimate survival (no date of diagnosis or zero follow-up time). Who were operated or took chemotherapy at other institutions and came to TASH for radiotherapy was also excluded. Outcomes Primary outcomes Treatment pattern – type and sequence of treatments received (surgery, chemotherapy, radiotherapy) Overall survival (OS) – time (months) from date of diagnosis to death from any cause or censoring at last follow-up Secondary outcomes Event-free survival (EFS) – time from diagnosis to disease progression, recurrence, or death Prognostic factors – variables associated with survival outcomes, assessed using Cox regression Statistical analysis All analyses were performed using IBM SPSS Statistics (Version 25). Descriptive statistics was used to summarize patient demographics, clinical characteristics, and treatment patterns. OS and EFS were estimated usisng Kaplan-Meier method and compared between groups with the log-rank test. Cox proportional hazards regression was used to analyze the association between patient demographics, disease characteristics, and different treatment modalities. Due to small sample size of our study, only clinical relevance covariates with p < = 0.25 on univariate analysis were considered for multivariable modeling to avoid overfitting, and predictors for survival were declared at a p-value of < 0.05. Missing data was minimal (< 6%), Therefore, descriptive and primary analyses were based on complete cases. Results Out of the seventy-five (69) patients with Ewing sarcoma diagnosed and treated at TASH from November 15, 2018, to November 15, 2023, sixty-one (n = 61) patients were met the inclusion criteria and included in this study. Socio-demographic and disease characteristics The median age at diagnosis was 19 years, with an age range of 5–50 years. Of this, 39.3% (n = 24) of the studied population were in the pediatric age group and 60.7% (n = 37) of them were adults (≥ 18) ( Table 1 ). Table 1: Socio-demographic and disease characteristics Patient characteristics (N=61) Frequency (n) % Age group (years) 0–­­­7 5 8.2 8–17 19 31.1 18–25 22 36.1 >25 15 24.6 Sex Female 40 65.6 Male 21 34.4 Stage Localized 48 78.7 Metastatic 13 21.3 Metastatic site 1 Lung 9 69.2 Lung + bone/bone marrow 1 7.6 Lung and other 2 15.3 Bone or bone marrow 1 7.6 Primary tumor size ≤8 cm 26 42.6 >8 cm 35 57.4 Disease origin Bone 55 90.1 Soft tissue 6 9.9 1 Percentages are based on the number of patients with metastatic disease (n=13) Treatment patterns Among the entire cohor, 73.8% received treatment with curative intent and 26.2% recieved palliative treatment. For localized cancer, the goal is curative for 94% of patients. However, 6% receive palliative care. Among patients treated with curative intent, the most common treatment modalities were chemotherapy combined with surgery (42.2%), followed by chemotherapy combined radiotherapy (40%), and tri-modalities therapy chemotherapy, surgery and radiotherapy (17.8%). All patients with metastatic disease were recieved palliative treatment. Adherence to standard treatment guideline was 16.7% for localized and 20% metastatic disease. Among patients treated with curative intent, 71.1% received neoadjuvant chemotherapy. Chemotherapy dosing schedules and treatment intensity varied by treating department: the paediatric hemato-oncology department administered an intensive regimen every two weeks, while the clinical oncology department used a conventional regimen every three weeks. The average number of chemotherapy cycles also varies by department. In pediatric hemato-oncology, it was 12 cycles, compared 6 cycles in clinical oncology department. The most common type of combination chemotherapy used in the radical treatment (97%) was vincristine, doxorubicin and cyclophosphamide alternating with ifosfamide and etoposide (VAC/IE). At treatment completion, based on radiological assessment by RECIST 1.1 criteria, 49.2% (n = 30) of the patients had complete response (CR), 39.3% (n = 24) and 6.6% had partial response (PR). Survival outcome Median follow-up time of the study by using the reverse Kaplan-Meier method is 34.0 months (95% CI: 28.7–39.2) with minimum and maximum follow up time of 8.0 to 59.0 month respectively. At the end of follow-up, 57.4% (n = 35) of the patients were alive, 32.8% (n = 20) had dead and the survival status was unknown in 9.8% (n = 6) of the cases. The median overall survival and event-free survival in the entire cohort were 45.0 and 24.0 month respectivel. The Kaplan–Meier estimated 1-year and 3-year OS rate for the entire cohort were 96% and 68%, respectively (Fig. 1A) , whereas the corresponding 1-year and 3-year EFS rate were 70% and 40%, respectively (Fig. 1B). Survival differed significantly by stage at disease at presentation. Patients with localized disease had superior outcomes, with a median OS not reached and median EFS of 32.0 months, whereas those with metastatic disease had a median OS of 23.0 months and a median EFS of 12.0 months. The 3-year OS and EFS rates were 89% and 76% for localized disease versus 10% and 0% for metastatic disease. This diffrence for both OS and EFS reaching statistical significance (log-rank p < 0.001) (Fig. 2A and 2B) Legends Figure 1: Kaplan–Meier survival curves for the entire cohort of patients with Ewing sarcoma. (A), Overall survival (OS) and (B), Event-free survival (EFS). Figure 2: Kaplan–Meier survival curves stratified by disease stage at diagnosis in patients with Ewing sarcoma. (A) Overall survival (OS) and (B) Event-free survival (EFS). (log-rank p < 0.001, for both). Prognostic factores We evaluated tumor size, stage of disease at doiagnosis, resection (surgery) was done or not, primary tumor pelvic location, and number of chemotherapy cycles by univariable and multivariable analyses to identify prognostic factors for OS and EFS. On multivariable analysis, tumor size ≤ 8 cm, localized stage, and receipt of surgery were independently associated with improved OS and EFS. Conversely, pelvic location in metastatic disease was associated with worse outcomes. The number of chemotherapy cycles in localized disease showed a non-significant trend toward better survival (Table 2 ) Table 2 Multivariable Cox regression analysis for overall and Event-free survival Variable Category HR (95% CI), OS P-value HR (95% CI), EFS P- value Tumor size ≤ 8 cm 0.13 (0.028–0.59) 0.045 0.28 (0.083–0.925) 0.037 > 8 cm 1 (Reference) 1 (Reference) Surgery as component of treatment Yes 0.22 (0.06–0.83) 0.025 0.2 (0.07–0.7 ) 0.01 No 1 (Reference) 1 (Reference) Stage of disease Localized 0.26 (0.103–0.655) 0.02 0.33 (0.1–0.8) 0.015 Metastatic 1 (Reference) 1 (Reference) Pelvic location (for metastatic disease) Yes 3.04 (1.26–7.4) 0.014 2.08 (1.2–4.4) 0.05 No 1 (Reference) 1 (Reference) Number of cycles of CT (for localized) ≥ 14 0.34 (0.07–1.5) 0.16 0.42 (0.12–1.2) 0.17 < 14 1 (Reference) 1 (Reference) HR: Hazard ratio; CI: Confidence interval; OS: Overall survival; EFS: Event-free survival, CT-Chemotheraapy Discussion To our knowledge, this is the first study from Sub-Saharan Africa and Ethiopia that report on the treatment patterns and survival outcomes of patients with Ewing sarcoma.This study therefore represents the first in the region that providing critical insight into the clinical characteristics, management, and outcomes of patients with Ewing sarcoma. In oure study, among the entire cohor, 73.8% received treatment with curative intent and 26.2% recieved palliative treatment. The type of treatment modality used was varie by stage of disease at diagnosis. For localized cancer, the goal is curative for 94% of patients, wheras all patients with metastatic disease were recieved palliative treatment. Among patients treated with curative intent, the most common treatment modalities were chemotherapy combined with surgery (42.2%), followed by chemotherapy combined radiotherapy (40%), and tri-modalities therapy chemotherapy, surgery and radiotherapy (17.8%). Adherence to standard treatment guideline was 16.7% for localized and 20% metastatic disease. When compared with reports from other settings, including low- and middle-income countries, the level of treatment protocol adherens in our cohort was relatively low. For example, a study from Egypt by Morsy et al. (2021) reported that, 75.3% of patients received treatment in accordance with standard treatment recomendation [ 13 ]. In our study, the median overall survival (OS) and event-free survival (EFS) in the entire cohort were 45.0 and 24.0 month respectivel. The Kaplan–Meier estimated 3-year OS and EFS rate for the entire cohort were 68% and 40%, respectively. Survival differed significantly by stage at diagnosis. Patients with localized disease had better outcomes, with a median OS not reached and median EFS of 32.0 months, whereas those with metastatic disease had a median OS of 23.0 months and a median EFS of 12.0 months. The 3-year OS and EFS rates were 89% and 76% for localized disease versus 10% and 0% for metastatic disease.The difference for both OS and EFS reaching statistical significance (log-rank p < 0.001). Smaller tumor size (≤ 8 cm) was the strongest favorable prognostic factor of OS and EFS followed by surgical intervention as as part of curative-intent treatment for patients with localized disease. For patients with metastatic disease, pelvic location of the primary tumor was independently associated with statistically significant poorer prognosis. Completion of standard number of chemotherapy cycles was associated with non- significant trend toward improved OS and EFS in patients with localized disease who were treated with radicaal intent. The Finding from our study is consistent with the result from low- and middle-income countries (LMIC). Egyptian study done by Morsy et.al.(2021), reported a 3-year OS and EFS of 42.5% and 50%, respectively acorss entire cohort of study. Furthermore, small tumor size and surgical intervention were identified as favorable prognostic factors for OS and EFS in this Egyptian study. However, unlike the Egyptian study, response to neoadjuvant chemotherapy was not statistically significant factors in this study [ 13 ]. Factors responsible for these differences may be adherence to standard treatment, which is 75% in the Egyptian study and less than 17% in our study. Finding of our study also compaarebaale to the findings from studies conducted in North east India and Iranian study [ 15 , 16 ]. Our study findings to the On St. Jude Children’s Research Hospital Studies review, the 3-year OS and EFS were about 70% and 58% respective which is higher than our finding. This study had larger samples (220 patients) and included only pediatric patients, unlike our study which was mixed population of 61 patients. In addition to this, radical treatment approach was applaied for majority of the patients with metastatic disease. However, size of the tumor, location, and stage of the disease were the independent predictors of outcome in that study which is simlilar to our finding [ 17 ]. Conclusion In conclusion, this first report from Ethiopia and potentialy from Sub-Saharan Africa demonstrates that survival outcome of patient with Ewing sarcoma are comparable to resource-limited countries However, but remain substantially inferior to outcomes from high-income settings. Disease stage at diagnosis, smaller tumor size, surgical intervention as part of curative-intent treatment were key favorable prognostic factors, whereas pelvic primary tumors were associated with poor outcomes in metastatic disease. In addion to this this study identifay low adherence to standard treatment guidelines, limited completion of recommended chemotherapy cycles, and the exclusive use of palliative care for metastatic disease. Thefore, strengthening adherence to standardized treatment guidline, promoting early diagnosis, and improving access to comprehensive multimodal therapy are essential to improve outcomes in resource-limited settings. Limitations of study This study has several limitations due to the retrospective nature of the study, single center design and smaller sample size. This study includes both pediatric and adult patients, which may introduce variability in treatment approaches, dosing schedules, and outcomes. Declarations Author contributions Conception/design: Tegene Gizaw Provision of study material or patients: Tegene Gizaw, Birhanu Tesfaye, Adugna Fikadu, Gashaw Arega and Sonia worku Collection and/or assembly of data: Tegene Gizaw, Birhanu Tisfaye, Feleke Hilemariam, Damena Teshome Data analysis and interpretation: Tegene Gizaw, Birhanu Tesfaye, Adugna Fikadu, Gashaw Arega, Sonia worku, Feleke Hailemariam and Damena Teshome Manuscript writing: Tegene Gizaw, Birhanu Tesfaye, Sonia worku Manuscript editing;- Tegene Gizaw, Birhanu Tesfaye, Adugna Fikadu, Gashaw Arega, Sonia worku and Damena Teshome Final approval of manuscript: All authors Accountable for all aspects of the work: All authors Funding The author(s) declare that no financial support was received for the research, authorship, and/or publication of this article. Conflicts of Interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be imposeas a potential conflict of interest. Ethics approval and consent to participate Ethical approval was obtained from Research and Ethics Committee of Addis Ababa University, College of Health Sciences, Ethiopia before initiating the study. The study was conducted in accordance with the principles of 1964 Helsinki declaration and its later amendments. Due to the retrospective nature of the study and the use of anonymized patient records, the requirement for informed consent to participate was waived by Research and Ethics Committee of Addis Ababa University, College of Health Sciences. The authors ensure that the rights of the patients are not violated in any manner. Consent for publication Not applicable Data availability statement The datasets analysed during the current study are available from the corresponding author on request. 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Federal Ministry of Health Ethiopia.National Strategic Action Plan (NSAP) for Prevention and Control of Non-Communicable Diseases in Ethiopia. Addis Ababa: FMOH; 2025 . Morsy AM, Abdel-Hadi S, Rezk KM, Amira G, Ahmed BM, Hussien MT, et al. Ewing sarcoma outcomes in a country with limited resources: Egypt as an example. Am J Cancer Res. 2021;11(6):3212–26. Gupta N, Pandey AK, Dimri K, Singh KK, Mishra A, Singh PK, et al. Real world data of Ewing sarcoma from a resource-limited setting with poor compliance to treatment leading to poor outcomes. Ecancermedicalscience. 2024;18:1801. Narayanan G, Suresh P, Rajan V, Janardhanan SK, Nair RA, Mathew A. Ewing's sarcoma in adolescents and adults – 10-year experience from a tertiary cancer center in India. J Cancer Res Ther. 2024;20(1):79–84. Esmati E, Maddah Safaei A, Babaei M, Nosrati H, Momeni H. Radiotherapy for Ewing sarcoma: A 5 year experience from Iran cancer institute. Internatuinal J Radiation Res. 2016;14(1):53–7. Rodríguez-Galindo C, Liu T, Krasin MJ, Wu J, Billups CA, Daw NC, et al. Analysis of prognostic factors in ewing sarcoma family of tumors: review of St. Jude Children's Research Hospital studies. Cancer. 2007;110(2):375–84. Additional Declarations No competing interests reported. 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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-9021771","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":603032510,"identity":"2320b636-b20c-4c8b-9381-ceeb760496ed","order_by":0,"name":"Tegene Gizaw","email":"","orcid":"","institution":"Ambo University","correspondingAuthor":false,"prefix":"","firstName":"Tegene","middleName":"","lastName":"Gizaw","suffix":""},{"id":603032511,"identity":"f7e20b5e-f08a-4429-9a66-5e86a27a2bda","order_by":1,"name":"Adugna Fikadu","email":"","orcid":"","institution":"Addis Ababa University","correspondingAuthor":false,"prefix":"","firstName":"Adugna","middleName":"","lastName":"Fikadu","suffix":""},{"id":603032512,"identity":"c548830e-4c14-4142-b325-3187629d2164","order_by":2,"name":"Gashaw Arega","email":"","orcid":"","institution":"Addis Ababa University","correspondingAuthor":false,"prefix":"","firstName":"Gashaw","middleName":"","lastName":"Arega","suffix":""},{"id":603032513,"identity":"34b7c4c5-3069-415c-8451-7d4a2840bd2e","order_by":3,"name":"Birhanu Tesfaye","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA1klEQVRIiWNgGAWjYBACA2Yg8cFAgpkfxEsoIFIL44wKG3bJBpAWA2K0ADEzz5k0foMDMC4hYM7O+/ABb9thaePzqxM/PDBgkOcXO4Bfi2Uzu7GBZNthY7MbbzdLAB1mOHN2AgGHHWZjkzBsO5xsduPsBpCWBIPbhLWw/0hsO1y/ecbZzT+I1cLGcOBMGrMBf+824myxbGZjlmyosGGWuMG7zSLBQIKwX8z5jzF+/gOKyv6zm2/+qLCR55cmoAUBJMAqJYhVDgL8B0hRPQpGwSgYBSMJAAB3PEF8wUNYqwAAAABJRU5ErkJggg==","orcid":"","institution":"Mizan-Tepi University","correspondingAuthor":true,"prefix":"","firstName":"Birhanu","middleName":"","lastName":"Tesfaye","suffix":""},{"id":603032514,"identity":"537a1d86-5bab-4972-b3f1-142c24efa934","order_by":4,"name":"Damena Teshome","email":"","orcid":"","institution":"Addis Ababa University","correspondingAuthor":false,"prefix":"","firstName":"Damena","middleName":"","lastName":"Teshome","suffix":""},{"id":603032515,"identity":"1d2c0fd3-103c-401a-b388-f664e3e0ee69","order_by":5,"name":"Sonia Worku","email":"","orcid":"","institution":"Addis Ababa University","correspondingAuthor":false,"prefix":"","firstName":"Sonia","middleName":"","lastName":"Worku","suffix":""},{"id":603032516,"identity":"c706bc27-0d42-4e31-9bc6-d5c655699723","order_by":6,"name":"Feleke Hailemariam","email":"","orcid":"","institution":"Saint Paul’s Hospital Millennium Medical College","correspondingAuthor":false,"prefix":"","firstName":"Feleke","middleName":"","lastName":"Hailemariam","suffix":""}],"badges":[],"createdAt":"2026-03-03 15:23:18","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9021771/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9021771/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104341362,"identity":"c404224e-bab1-4b6f-8158-44ec512c53a8","added_by":"auto","created_at":"2026-03-10 16:49:05","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":78656,"visible":true,"origin":"","legend":"\u003cp\u003eKaplan–Meier survival curves for the entire cohort of patients with Ewing sarcoma. (A), Overall survival (OS) and (B), Event-free survival (EFS).\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9021771/v1/c576bc6aa7499729fa670016.png"},{"id":104405741,"identity":"437a9b5e-32c6-4995-b0ce-8753acf46d6b","added_by":"auto","created_at":"2026-03-11 12:23:42","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":110081,"visible":true,"origin":"","legend":"\u003cp\u003eKaplan–Meier survival curves stratified by disease stage at diagnosis in patients with Ewing sarcoma. (A) Overall survival (OS) and (B) Event-free survival (EFS). (log-rank p \u0026lt; 0.001, for both).\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-9021771/v1/e1d72fd4076732f4bf3bbd2b.png"},{"id":104409621,"identity":"aee3b08c-1ece-479f-b24e-ea8f1e53da1e","added_by":"auto","created_at":"2026-03-11 12:46:14","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":800099,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9021771/v1/9d1ce69d-344c-4146-9b50-4bbf8829657d.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Treatment patterns and survival outcomes of Ewing sarcoma in Ethiopia: A five-year retrospective analysis from a tertiary hospital","fulltext":[{"header":"Introduction","content":"\u003cp\u003eEwing sarcoma (ES) is a malignant small round-cell tumor of bone or soft tissue characterized by rearrangements of Ewing Sarcoma RNA binding protein 1 (EWSR1) gene and members of the E26 transformation-specific (ETS) transcription factor family [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. It is the third most common primary bone malignancy overall and the second most common primary bone malignancy in pediatrics and adolescents group, comprising approximately 2\u0026ndash;3% of all malignancies in this age group. Although its incidence is unknown in older populations, approximately 30% of cases occur in individuals older than 20 years [\u003cspan additionalcitationids=\"CR5 CR6 CR7\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eUnlike most other bone and soft tissue sarcomas, ES is highly sensitivity to both systemic multiagent chemotherapy and radiotherapy. Over the past few decades, data from developed countries have shown that, the 5-year survival rate has improved from 10% to over 70% for localized disease and from 0% to 30% for metastatic disease [\u003cspan additionalcitationids=\"CR9 CR10 CR11\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. However data on treatment patterns and survival outcome from low- and middle-income countries are limited. Available reports suggest that 5-year survival for localized disease ranges from 35\u0026ndash;69%, and about 4% for metastatic disease. To best of our knowledge, no published data exist on survival and treatment modality Ewing sarcoma from Sub-Saharan Africa including Ethiopia [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTherefore the aim of this study is to evaluate the treatment patterns and survival outcome of patients with Ewing sarcoma at Tikur Anbessa Hospital, Ethiopia. The finding will provide locally relevant evidence to inform clinical decision-making and optimize resources allocation, while also establishing a foundation for future prospective research in resource-limited settings.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design and setting\u003c/h2\u003e \u003cp\u003e This retrospective cohort study was conducted at Tikur Anbessa Specialized Hospital (TASH), Addis Ababa University, Ethiopia\u0026rsquo;s which is largest tertiary referral center and the country\u0026rsquo;s leading facility for comprehensive cancer care, including chemotherapy, radiotherapy, surgery, and palliative services.The study was performed in the adult oncology department and Pediatric Hematology\u0026ndash;Oncology Unit.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eStudy population, sample size and eligibility criteria\u003c/h3\u003e\n\u003cp\u003eDue to small total number of population under investigation (n\u0026thinsp;=\u0026thinsp;61), all consecutive pediatric and adult patients diagnosed with Ewing sarcoma and treated at Tikur Anbessa Specialized Hospital during the 5-year period (November 15, 2018, to November 15, 2023) who met the inclusion and exclusion criteria were included. Patients were excluded if they had missing data on key variables to estimate survival (no date of diagnosis or zero follow-up time). Who were operated or took chemotherapy at other institutions and came to TASH for radiotherapy was also excluded.\u003c/p\u003e\n\u003ch3\u003eOutcomes\u003c/h3\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003ePrimary outcomes\u003c/h2\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eTreatment pattern \u0026ndash; type and sequence of treatments received (surgery, chemotherapy, radiotherapy)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eOverall survival (OS) \u0026ndash; time (months) from date of diagnosis to death from any cause or censoring at last follow-up\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSecondary outcomes\u003c/h3\u003e\n\u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eEvent-free survival (EFS) \u0026ndash; time from diagnosis to disease progression, recurrence, or death\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003ePrognostic factors \u0026ndash; variables associated with survival outcomes, assessed using Cox regression\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eAll analyses were performed using IBM SPSS Statistics (Version 25). Descriptive statistics was used to summarize patient demographics, clinical characteristics, and treatment patterns. OS and EFS were estimated usisng Kaplan-Meier method and compared between groups with the log-rank test. Cox proportional hazards regression was used to analyze the association between patient demographics, disease characteristics, and different treatment modalities. Due to small sample size of our study, only clinical relevance covariates with p\u0026thinsp;\u0026lt;\u0026thinsp;=\u0026thinsp;0.25 on univariate analysis were considered for multivariable modeling to avoid overfitting, and predictors for survival were declared at a p-value of \u0026lt;\u0026thinsp;0.05. Missing data was minimal (\u0026lt;\u0026thinsp;6%), Therefore, descriptive and primary analyses were based on complete cases.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e Out of the seventy-five (69) patients with Ewing sarcoma diagnosed and treated at TASH from November 15, 2018, to November 15, 2023, sixty-one (n\u0026thinsp;=\u0026thinsp;61) patients were met the inclusion criteria and included in this study.\u003c/p\u003e\n\u003ch3\u003eSocio-demographic and disease characteristics\u003c/h3\u003e\n\u003cp\u003eThe median age at diagnosis was 19 years, with an age range of 5\u0026ndash;50 years. Of this, 39.3% (n\u0026thinsp;=\u0026thinsp;24) of the studied population were in the pediatric age group and 60.7% (n\u0026thinsp;=\u0026thinsp;37) of them were adults (\u0026ge;\u0026thinsp;18) \u003cb\u003e(\u003c/b\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e\u003cb\u003e).\u003c/b\u003e\u003c/p\u003e\u003cp\u003eTable 1: Socio-demographic and disease characteristics\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"90%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 50px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePatient \u0026nbsp;characteristics (N=61)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFrequency (n)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\" valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge group (years)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003e0\u0026ndash;\u0026shy;\u0026shy;\u0026shy;7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e8.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003e8\u0026ndash;17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e31.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003e18\u0026ndash;25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e36.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026gt;25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e24.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSex\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e65.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e34.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eStage\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003eLocalized\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e78.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003eMetastatic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e21.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\" valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMetastatic site\u003csup\u003e1\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003eLung\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e69.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003eLung + bone/bone marrow\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e7.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003eLung and other\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e15.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003eBone or bone marrow\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e7.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePrimary tumor size\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026le;8 cm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e42.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026gt;8 cm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e57.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eDisease origin\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003eBone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e90.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 25px;\"\u003e\n \u003cp\u003eSoft tissue\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 22px;\"\u003e\n \u003cp\u003e9.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003ePercentages are based on the number of patients with metastatic disease (n=13)\u003c/p\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eTreatment patterns\u003c/h2\u003e \u003cp\u003eAmong the entire cohor, 73.8% received treatment with curative intent and 26.2% recieved palliative treatment. For localized cancer, the goal is curative for 94% of patients. However, 6% receive palliative care. Among patients treated with curative intent, the most common treatment modalities were chemotherapy combined with surgery (42.2%), followed by chemotherapy combined radiotherapy (40%), and tri-modalities therapy chemotherapy, surgery and radiotherapy (17.8%). All patients with metastatic disease were recieved palliative treatment.\u003c/p\u003e \u003cp\u003e Adherence to standard treatment guideline was 16.7% for localized and 20% metastatic disease. Among patients treated with curative intent, 71.1% received neoadjuvant chemotherapy. Chemotherapy dosing schedules and treatment intensity varied by treating department: the paediatric hemato-oncology department administered an intensive regimen every two weeks, while the clinical oncology department used a conventional regimen every three weeks. The average number of chemotherapy cycles also varies by department. In pediatric hemato-oncology, it was 12 cycles, compared 6 cycles in clinical oncology department. The most common type of combination chemotherapy used in the radical treatment (97%) was vincristine, doxorubicin and cyclophosphamide alternating with ifosfamide and etoposide (VAC/IE).\u003c/p\u003e \u003cp\u003eAt treatment completion, based on radiological assessment by RECIST 1.1 criteria, 49.2% (n\u0026thinsp;=\u0026thinsp;30) of the patients had complete response (CR), 39.3% (n\u0026thinsp;=\u0026thinsp;24) and 6.6% had partial response (PR).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eSurvival outcome\u003c/h2\u003e \u003cp\u003eMedian follow-up time of the study by using the reverse Kaplan-Meier method is 34.0 months (95% CI: 28.7\u0026ndash;39.2) with minimum and maximum follow up time of 8.0 to 59.0 month respectively. At the end of follow-up, 57.4% (n\u0026thinsp;=\u0026thinsp;35) of the patients were alive, 32.8% (n\u0026thinsp;=\u0026thinsp;20) had dead and the survival status was unknown in 9.8% (n\u0026thinsp;=\u0026thinsp;6) of the cases.\u003c/p\u003e \u003cp\u003eThe median overall survival and event-free survival in the entire cohort were 45.0 and 24.0 month respectivel. The Kaplan\u0026ndash;Meier estimated 1-year and 3-year OS rate for the entire cohort were 96% and 68%, respectively \u003cb\u003e(Fig.\u0026nbsp;1A)\u003c/b\u003e, whereas the corresponding 1-year and 3-year EFS rate were 70% and 40%, respectively (Fig.\u0026nbsp;1B).\u003c/p\u003e \u003cp\u003eSurvival differed significantly by stage at disease at presentation. Patients with localized disease had superior outcomes, with a median OS not reached and median EFS of 32.0 months, whereas those with metastatic disease had a median OS of 23.0 months and a median EFS of 12.0 months. The 3-year OS and EFS rates were 89% and 76% for localized disease versus 10% and 0% for metastatic disease. This diffrence for both OS and EFS reaching statistical significance (log-rank p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Fig.\u0026nbsp;2A and 2B)\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eLegends\u003c/h2\u003e \u003cp\u003eFigure 1: Kaplan\u0026ndash;Meier survival curves for the entire cohort of patients with Ewing sarcoma. (A), Overall survival (OS) and (B), Event-free survival (EFS).\u003c/p\u003e \u003cp\u003eFigure 2: Kaplan\u0026ndash;Meier survival curves stratified by disease stage at diagnosis in patients with Ewing sarcoma. (A) Overall survival (OS) and (B) Event-free survival (EFS). (log-rank p\u0026thinsp;\u0026lt;\u0026thinsp;0.001, for both).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003ePrognostic factores\u003c/h2\u003e \u003cp\u003eWe evaluated tumor size, stage of disease at doiagnosis, resection (surgery) was done or not, primary tumor pelvic location, and number of chemotherapy cycles by univariable and multivariable analyses to identify prognostic factors for OS and EFS.\u003c/p\u003e \u003cp\u003eOn multivariable analysis, tumor size\u0026thinsp;\u0026le;\u0026thinsp;8 cm, localized stage, and receipt of surgery were independently associated with improved OS and EFS. Conversely, pelvic location in metastatic disease was associated with worse outcomes. The number of chemotherapy cycles in localized disease showed a non-significant trend toward better survival (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e)\u003c/p\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\u003eMultivariable Cox regression analysis for overall and Event-free survival\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=\"char\" char=\".\" 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=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCategory\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHR (95% CI), OS\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eP-value\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHR (95% CI), EFS\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eP- value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTumor size\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026le;\u0026thinsp;8 cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.13 (0.028\u0026ndash;0.59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.045\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.28 (0.083\u0026ndash;0.925)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.037\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;8 cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (Reference)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (Reference)\u003c/p\u003e \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\u003eSurgery as component of treatment\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\u003e0.22 (0.06\u0026ndash;0.83)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.025\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.2 (0.07\u0026ndash;0.7 )\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.01\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 (Reference)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (Reference)\u003c/p\u003e \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\u003eStage of disease\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLocalized\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.26 (0.103\u0026ndash;0.655)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.33 (0.1\u0026ndash;0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.015\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMetastatic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (Reference)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (Reference)\u003c/p\u003e \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\u003ePelvic location (for metastatic disease)\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\u003e3.04 (1.26\u0026ndash;7.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.014\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.08 (1.2\u0026ndash;4.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.05\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 (Reference)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (Reference)\u003c/p\u003e \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\u003eNumber of cycles of CT (for localized)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.34 (0.07\u0026ndash;1.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.42 (0.12\u0026ndash;1.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (Reference)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (Reference)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eHR: Hazard ratio; CI: Confidence interval; OS: Overall survival; EFS: Event-free survival, CT-Chemotheraapy\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eTo our knowledge, this is the first study from Sub-Saharan Africa and Ethiopia that report on the treatment patterns and survival outcomes of patients with Ewing sarcoma.This study therefore represents the first in the region that providing critical insight into the clinical characteristics, management, and outcomes of patients with Ewing sarcoma.\u003c/p\u003e \u003cp\u003eIn oure study, among the entire cohor, 73.8% received treatment with curative intent and 26.2% recieved palliative treatment. The type of treatment modality used was varie by stage of disease at diagnosis. For localized cancer, the goal is curative for 94% of patients, wheras all patients with metastatic disease were recieved palliative treatment. Among patients treated with curative intent, the most common treatment modalities were chemotherapy combined with surgery (42.2%), followed by chemotherapy combined radiotherapy (40%), and tri-modalities therapy chemotherapy, surgery and radiotherapy (17.8%). Adherence to standard treatment guideline was 16.7% for localized and 20% metastatic disease. When compared with reports from other settings, including low- and middle-income countries, the level of treatment protocol adherens in our cohort was relatively low. For example, a study from Egypt by Morsy et al. (2021) reported that, 75.3% of patients received treatment in accordance with standard treatment recomendation [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn our study, the median overall survival (OS) and event-free survival (EFS) in the entire cohort were 45.0 and 24.0 month respectivel. The Kaplan\u0026ndash;Meier estimated 3-year OS and EFS rate for the entire cohort were 68% and 40%, respectively. Survival differed significantly by stage at diagnosis. Patients with localized disease had better outcomes, with a median OS not reached and median EFS of 32.0 months, whereas those with metastatic disease had a median OS of 23.0 months and a median EFS of 12.0 months. The 3-year OS and EFS rates were 89% and 76% for localized disease versus 10% and 0% for metastatic disease.The difference for both OS and EFS reaching statistical significance (log-rank p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Smaller tumor size (\u0026le;\u0026thinsp;8 cm) was the strongest favorable prognostic factor of OS and EFS followed by surgical intervention as as part of curative-intent treatment for patients with localized disease. For patients with metastatic disease, pelvic location of the primary tumor was independently associated with statistically significant poorer prognosis. Completion of standard number of chemotherapy cycles was associated with non- significant trend toward improved OS and EFS in patients with localized disease who were treated with radicaal intent.\u003c/p\u003e \u003cp\u003eThe Finding from our study is consistent with the result from low- and middle-income countries (LMIC). Egyptian study done by Morsy et.al.(2021), reported a 3-year OS and EFS of 42.5% and 50%, respectively acorss entire cohort of study. Furthermore, small tumor size and surgical intervention were identified as favorable prognostic factors for OS and EFS in this Egyptian study. However, unlike the Egyptian study, response to neoadjuvant chemotherapy was not statistically significant factors in this study [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Factors responsible for these differences may be adherence to standard treatment, which is 75% in the Egyptian study and less than 17% in our study. Finding of our study also compaarebaale to the findings from studies conducted in North east India and Iranian study [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOur study findings to the\u003c/p\u003e \u003cp\u003eOn St. Jude Children\u0026rsquo;s Research Hospital Studies review, the 3-year OS and EFS were about 70% and 58% respective which is higher than our finding. This study had larger samples (220 patients) and included only pediatric patients, unlike our study which was mixed population of 61 patients. In addition to this, radical treatment approach was applaied for majority of the patients with metastatic disease. However, size of the tumor, location, and stage of the disease were the independent predictors of outcome in that study which is simlilar to our finding [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn conclusion, this first report from Ethiopia and potentialy from Sub-Saharan Africa demonstrates that survival outcome of patient with Ewing sarcoma are comparable to resource-limited countries However, but remain substantially inferior to outcomes from high-income settings. Disease stage at diagnosis, smaller tumor size, surgical intervention as part of curative-intent treatment were key favorable prognostic factors, whereas pelvic primary tumors were associated with poor outcomes in metastatic disease. In addion to this this study identifay low adherence to standard treatment guidelines, limited completion of recommended chemotherapy cycles, and the exclusive use of palliative care for metastatic disease. Thefore, strengthening adherence to standardized treatment guidline, promoting early diagnosis, and improving access to comprehensive multimodal therapy are essential to improve outcomes in resource-limited settings.\u003c/p\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003eLimitations of study\u003c/h2\u003e \u003cp\u003eThis study has several limitations due to the retrospective nature of the study, single center design and smaller sample size. This study includes both pediatric and adult patients, which may introduce variability in treatment approaches, dosing schedules, and outcomes.\u003c/p\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003eAuthor contributions\u003c/p\u003e\n\u003cp\u003eConception/design: Tegene Gizaw\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Provision of study material or patients: Tegene Gizaw, Birhanu Tesfaye, Adugna Fikadu, Gashaw Arega and Sonia worku\u003c/p\u003e\n\u003cp\u003eCollection and/or assembly of data: Tegene Gizaw, Birhanu Tisfaye, Feleke Hilemariam, Damena Teshome\u003c/p\u003e\n\u003cp\u003eData analysis and interpretation: Tegene Gizaw, Birhanu Tesfaye, Adugna Fikadu, Gashaw Arega, Sonia worku, Feleke Hailemariam and Damena Teshome\u003c/p\u003e\n\u003cp\u003eManuscript writing: Tegene Gizaw, Birhanu Tesfaye, Sonia worku\u003c/p\u003e\n\u003cp\u003eManuscript editing;- Tegene Gizaw, Birhanu Tesfaye, Adugna Fikadu, Gashaw Arega, Sonia worku and Damena Teshome\u003c/p\u003e\n\u003cp\u003eFinal approval of manuscript: All authors\u003c/p\u003e\n\u003cp\u003eAccountable for all aspects of the work: All authors\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003eThe author(s) declare that no financial support was received for the research, authorship, and/or publication of this article.\u003c/p\u003e\n\u003cp\u003eConflicts of Interest\u003c/p\u003e\n\u003cp\u003eThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be imposeas a potential conflict of interest.\u003c/p\u003e\n\u003cp\u003eEthics approval and consent to participate\u003c/p\u003e\n\u003cp\u003eEthical approval was obtained from Research and Ethics Committee of Addis Ababa University, College of Health Sciences, Ethiopia before initiating the study. The study was conducted in accordance with the principles of 1964 Helsinki declaration and its later amendments. Due to the retrospective nature of the study and the use of anonymized patient records, the requirement for informed consent to participate was waived by Research and Ethics Committee of Addis Ababa University, College of Health Sciences. The authors ensure that the rights of the patients are not violated in any manner.\u003c/p\u003e\n\u003cp\u003eConsent for publication\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003eData availability statement\u003c/p\u003e\n\u003cp\u003eThe datasets analysed during the current study are available from the corresponding author on request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBoard WCoTE. Soft Tissue and Bone Tumours. 5th ed. International Agency for Research on Cancer; 2020.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGrier HE. The Ewing family of tumors: Ewing\u0026rsquo;s sarcoma and primitive neuroectodermal tumors. Pediatr Oncol. 1997;44:991\u0026ndash;1004.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJaffe R, Santamaria M, Yunis EJ, Tannery NH, Agostini RM, Medina J, et al. The neuroectodermal tumor of bone. Am J Surg Pathol. 1984;8(12):885\u0026ndash;98.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHornicek FJ, Bernstein M, Baldini EH. \u003cem\u003eEpidemiology, pathology, and molecular genetics of Ewing sarcoma\u003c/em\u003e. 2025 [cited 29/10/2025; Available from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.uptodate.com/contents/epidemiology-pathology-and-molecular-genetics-of-ewing-sarcoma?utm_source=chatgpt.com\u003c/span\u003e\u003cspan address=\"https://www.uptodate.com/contents/epidemiology-pathology-and-molecular-genetics-of-ewing-sarcoma?utm_source=chatgpt.com\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSpector LG, Hubbard A, Poynter JN, Neglia JP, Smith S, Robison LL, et al. Comparative international incidence of Ewing sarcoma 1988 to 2012. Int J Cancer. 2021;149(5):1054\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBirch JM, Alston RD, Kelsey AM, Quinn MJ, Babb P, McNally RJ. Classification and incidence of cancers in adolescents and young adults in England 1979\u0026ndash;1997. Br J Cancer. 2002;87(11):1267\u0026ndash;74.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBernstein M, Kovar H, Paulussen M, Randall RL, Schuck A, Teot LA, et al. Ewing\u0026rsquo;s sarcoma family of tumors: current management. Oncologist. 2006;11:503\u0026ndash;19.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLingerih T, Assefa B, Ayalew T, Zenebe Y, Woldetsadik E, Girma B. Patterns and treatment outcomes of primary bone tumors in children treated at tertiary referral hospital, Ethiopia. BMC Cancer. 2024;24(1):394.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePotratz J, Dirksen U, J\u0026uuml;rgens H, Craft A. Ewing sarcoma: clinical state-of-the-art. Pediatr Hematol Oncol. 2012;29(1):1\u0026ndash;11.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGatta G, Capocaccia R, Stiller C, Kaatsch P, Berrino F, Terenziani M, et al. Childhood cancer survival trends in Europe: a EUROCARE Working Group study. J Clin Oncol. 2005;23(16):3742\u0026ndash;51.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBray F, Laversanne M, Sung H, Ferlay J, Siegel RL, Soerjomataram I, et al. GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2024;74(3):229\u0026ndash;63.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003e\u003cem\u003eFederal Ministry of Health Ethiopia.National Strategic Action Plan (NSAP) for Prevention and Control of Non-Communicable Diseases in Ethiopia. Addis Ababa: FMOH; 2025\u003c/em\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMorsy AM, Abdel-Hadi S, Rezk KM, Amira G, Ahmed BM, Hussien MT, et al. Ewing sarcoma outcomes in a country with limited resources: Egypt as an example. Am J Cancer Res. 2021;11(6):3212\u0026ndash;26.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGupta N, Pandey AK, Dimri K, Singh KK, Mishra A, Singh PK, et al. Real world data of Ewing sarcoma from a resource-limited setting with poor compliance to treatment leading to poor outcomes. Ecancermedicalscience. 2024;18:1801.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNarayanan G, Suresh P, Rajan V, Janardhanan SK, Nair RA, Mathew A. Ewing's sarcoma in adolescents and adults\u0026thinsp;\u0026ndash;\u0026thinsp;10-year experience from a tertiary cancer center in India. J Cancer Res Ther. 2024;20(1):79\u0026ndash;84.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEsmati E, Maddah Safaei A, Babaei M, Nosrati H, Momeni H. Radiotherapy for Ewing sarcoma: A 5 year experience from Iran cancer institute. Internatuinal J Radiation Res. 2016;14(1):53\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRodr\u0026iacute;guez-Galindo C, Liu T, Krasin MJ, Wu J, Billups CA, Daw NC, et al. Analysis of prognostic factors in ewing sarcoma family of tumors: review of St. Jude Children's Research Hospital studies. Cancer. 2007;110(2):375\u0026ndash;84.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"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-cancer","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bcan","sideBox":"Learn more about [BMC Cancer](http://bmccancer.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bcan/default.aspx","title":"BMC Cancer","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Ewing sarcoma, bone tumor, treatment pattern survival, TASH, Ethiopia","lastPublishedDoi":"10.21203/rs.3.rs-9021771/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9021771/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e: Ewing sarcoma is a malignant small round-cell sarcoma of bone or soft tissue that is highly responsive to modern multimodal therapy and considered as highly curable disease developed countries. However, survival remains poor in developing countries.This study aims to assess treatment patterns and survival outcomes of Ewing sarcoma at Tikur Anbessa Hospital.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods and Materials\u003c/strong\u003e: we conducted a retrospective study on all patient diagnosed with Ewing sarcoma at Tikur Anbessa Hospital between November 15, 2018, and November 15, 2023. \u0026nbsp;Descriptive statistics and Kaplan-Meier survival analysis were used to analyze the data.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResult\u003c/strong\u003e: The median age at diagnosis was 19 years, with most of the patients (67.2%) in the age range of 8-25 year. \u0026nbsp;The main modality of treatment for localized disease was chemotherapy combined with surgery, whereas chemotherapy alone was used for metastatic disease. The 3-year overall survival (OS) and event-free survival (EFS) for entire cohort were 68%% and 40%, respectively. The 3-year OS and EFS rates were 89% and 76% for localized disease versus 10% and 0% for metastatic disease.This diffrence for both OS and EFS reaching statistical significance (log-rank p \u0026lt; 0.001).\u003c/p\u003e\n\u003cp\u003eSmall tumor size (≤ 8 cm), surgical intervention and localized stage were associated with statistically significant improvement in OS and EFS, whereas pelvic location was poorer prognosis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e: Ewing sarcoma at our institution mainly affects adolescents and young adults. Survival is poor, especially for metastatic disease, while localized tumors, smaller size, and surgery are associated with better survival. Theirfor early diagnosis and improved multimodal treatment are needed to improve survival.\u003c/p\u003e","manuscriptTitle":"Treatment patterns and survival outcomes of Ewing sarcoma in Ethiopia: A five-year retrospective analysis from a tertiary hospital","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-10 16:49:01","doi":"10.21203/rs.3.rs-9021771/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-15T08:04:29+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-14T08:46:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"37666791794692535436162472313401191185","date":"2026-04-09T11:58:52+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"247145537042808728621993860404933232800","date":"2026-04-08T23:59:54+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-07T17:45:37+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-06T21:04:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"274448503403566141135850833298677436102","date":"2026-04-05T07:43:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"201315847943298466768591526508437684707","date":"2026-04-03T05:10:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"56052975974269365781757422002553407211","date":"2026-04-02T10:39:40+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-02T08:44:31+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-31T04:23:24+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-03-09T10:26:10+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-06T16:38:21+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Cancer","date":"2026-03-06T15:01:31+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-cancer","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bcan","sideBox":"Learn more about [BMC Cancer](http://bmccancer.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bcan/default.aspx","title":"BMC Cancer","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"9c2db698-dc9b-4edf-901b-d7c8fe1ef4f5","owner":[],"postedDate":"March 10th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-18T06:54:51+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-10 16:49:01","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9021771","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9021771","identity":"rs-9021771","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}