Expression Differences and Clinical Significance of PD-L1 in Lung Cancer Patients with Different Histological Types and Differentiation Degrees

Expression Differences and Clinical Significance of PD-L1 in Lung Cancer Patients with Different Histological Types and Differentiation Degrees | 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 Expression Differences and Clinical Significance of PD-L1 in Lung Cancer Patients with Different Histological Types and Differentiation Degrees Xincheng Zhou, Shuang Ao, Yanan Guo, Jing Jin This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8753810/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract Objective To investigate the expression differences of PD-L1 in lung cancer patients with different histological types and differentiation degrees. Methods A retrospective analysis was conducted on the clinical data of 544 patients diagnosed with lung cancer at Ningbo Pathological Diagnosis Center. The differences in PD-L1 expression levels among different histological subtypes of lung cancer and the relationship between PD-L1 level and differentiation degree were compared. Results There was a statistically significant difference in PD-L1 level between genders (P 0.05). No significant differences in histological types were observed between genders or age groups (P > 0.05). However, differentiation degrees showed significant differences between genders and age groups (P < 0.001). The proportion of adenocarcinoma patients with negative PD-L1 expression was significantly higher than that of squamous cell carcinoma patients (32.45% vs. 19.92%), while the proportions of adenocarcinoma patients with low and high PD-L1 expression were lower than those of squamous cell carcinoma patients (48.34% vs. 50.00%; 19.21% vs. 30.08%) (P < 0.001). The proportion of well-differentiated patients with negative PD-L1 expression was significantly higher than that of moderately and poorly differentiated patients (45.71% vs. 38.73% vs. 14.39%), and the proportion of well-differentiated patients with high PD-L1 expression was significantly lower than that of moderately and poorly differentiated patients (8.57% vs. 13.73% vs. 35.98%) (P < 0.001). Among well-differentiated patients with negative PD-L1 expression, the proportion of adenocarcinoma was significantly higher than that of squamous cell carcinoma and small cell carcinoma (61.11% vs. 29.41% vs. 0.00%) (P < 0.05). Among well-differentiated patients with low PD-L1 expression, the proportion of squamous cell carcinoma was higher than that of adenocarcinoma and small cell carcinoma (52.94% vs. 38.89% vs. 0.00%) (P < 0.05). Conclusion PD-L1 level is correlated with histological subtype, with higher PD-L1 levels in squamous cell carcinoma patients compared to adenocarcinoma patients. PD-L1 level is also correlated with differentiation degree, with lower PD-L1 levels in well-differentiated patients compared to poorly differentiated patients. Both PD-L1 level and differentiation degree in small cell lung cancer patients are lower than those in adenocarcinoma and squamous cell carcinoma patients. Chinese Library Classification Number: R737.1 Document Identification Code: A PD-L1 Lung cancer Histological type Differentiation degree Immunotherapy Introduction Programmed death ligand 1 (PD-L1) is currently the most extensively studied inhibitory immune checkpoint molecule, and its expression level has become one of the primary biomarkers for predicting the efficacy of immunotherapy in lung cancer patients. Numerous large-scale clinical trials have shown that patients with high PD-L1 expression respond better to PD-1/PD-L1 inhibitor therapy[1–2]. Both NCCN and CSCO guidelines explicitly recommend different immunotherapy strategies based on the immunohistochemical expression level of PD-L1 in lung cancer patients[3–4]. However, PD-L1 expression in lung cancer is highly heterogeneous, and its expression patterns across different histological types and differentiation degrees require further clarification. Existing studies suggest that PD-L1 expression is higher in lung squamous cell carcinoma than in lung adenocarcinoma[5], and differentiation degree may be negatively correlated with PD-L1 expression[6]. Data on PD-L1 expression in small cell lung cancer remain controversial[7–9], and its clinical significance warrants further investigation. Immune checkpoint inhibitors targeting PD-1/PD-L1 have shown clinical activity in small cell lung cancer treatment[10]. This study retrospectively analyzed PD-L1 expression data from 544 lung cancer patients to systematically evaluate its relationship with histological type and differentiation degree, aiming to provide pathological evidence for individualized immunotherapy strategies in lung cancer. 1. Materials and Methods 1.1 General Information A total of 544 patients diagnosed with lung cancer at Ningbo Pathological Diagnosis Center from August 2023 to March 2024 were selected as the study subjects. Among them, 134 were female and 410 were male; 139 were ≤ 60 years old and 405 were > 60 years old. Histological types included 302 cases of adenocarcinoma, 236 cases of squamous cell carcinoma, and 6 cases of small cell carcinoma. Differentiation degrees were classified as 270 poorly differentiated, 204 moderately differentiated, and 70 well-differentiated cases. 1.2 Inclusion and Exclusion Criteria Inclusion criteria: ① Age 18–90 years; ② Signed informed consent; ③ Pathologically confirmed diagnosis of lung cancer; ④ Complete PD-L1 immunohistochemical test results available. Exclusion criteria: ① Pathological diagnosis other than lung cancer; ② No PD-L1 test results; ③ Incomplete clinical data. 1.3 Detection Methods PD-L1 expression was detected using immunohistochemistry with PD-L1 antibody (clone 22C3). Tumor proportion score (TPS) was used as the expression standard: TPS < 1% was considered negative, 1%–49% as low expression, and ≥ 50% as high expression. Differentiation degree was graded according to the WHO Classification of Thoracic Tumours (5th edition)[11]. 1.4 Statistical Methods Statistical analysis was performed using SPSS 26.0 software. PD-L1 IHC results (TPS < 1%, 1%–49%, ≥ 50%) were assigned values of 0, 1, and 2, respectively. Chi-square test was used to analyze whether there were differences in PD-L1 expression among different groups (e.g., gender, age, histological type, differentiation degree), with a P value < 0.05 considered statistically significant. 2. Results 2.1 Relationship Between PD-L1 Expression and Clinical Characteristics PD-L1 expression showed significant differences between genders (P 0.05). Differentiation degree showed significant differences in both gender and age groups (P 60 years old. Table 1 Relationship Between PD-L1 Expression and Gender/Age in Lung Cancer Patients (n = 544) Group Number (%) PD-L1 Negative(n, %) Low Expression(n, %) High Expression(n, %) P Value Gender 0.0000 Male 41(75.37) 94(22.93) 203(49.51) 11(27.56) Female 13(24.63) 55(41.04) 63(47.01) 16(11.94) Age 0.7075 ≤ 60 13(25.55) 35(25.18) 72(51.80) 32(23.02) >60 40(74.45) 11(28.15) 194(47.90) 97(23.95) Total 544 14(27.39) 266(48.90) 12(23.71) 2.2 Relationship Between PD-L1 Expression and Histological Type The proportion of adenocarcinoma patients with negative PD-L1 expression was significantly higher than that of squamous cell carcinoma patients (32.45% vs. 19.92%), while the proportion of adenocarcinoma patients with high PD-L1 expression was lower than that of squamous cell carcinoma patients (19.21% vs. 30.08%) (P < 0.001). Small cell carcinoma patients had the highest proportion of negative PD-L1 expression (66.67%), with no cases showing high expression. Table 2 Relationship Between PD-L1 Expression and Histological Type in Lung Cancer Patients (n = 544) Histological Type Number(%) PD-L1 Negative(n, %) Low Expression(n, %) High Expression(n, %) P Value 0.0006 Adenocarcinoma 30(55.51) 98(32.45) 146(48.34) 5(19.21) Squamous Cell Carcinoma 23(43.38) 47(19.92) 118(50.00) 7(30.08) Small Cell Carcinoma 6(1.10) 4(66.67) 2(33.33) 0(0.00) Total 544 149 266 129 2.3 Relationship Between PD-L1 Expression and Differentiation Degree Well-differentiated patients had the highest proportion of negative PD-L1 expression (45.71%) and the lowest proportion of high PD-L1 expression (8.57%). Poorly differentiated patients showed a significantly increased proportion of high PD-L1 expression (35.98%) (P < 0.001). Table 3 Relationship Between PD-L1 Expression and Differentiation Degree in Lung Cancer Patients (n = 544) Differentiation Degree Number (%) PD-L1 Negative (n, %) Low Expression (n, %) High Expression (n, %) Poorly Differentiated 264(48.53) 38(14.39) 137(51.89) 95(35.98) Moderately Differentiated 204(37.50) 79(38.73) 97(47.55) 28(13.73) Well-Differentiated 70(12.87) 32(45.71) 32(45.71) 6(8.57) Total 544 149 266 129 2.4 Interrelationship Among PD-L1 Expression, Differentiation Degree, and Histological Type Among poorly differentiated patients with negative PD-L1 expression, the proportions of adenocarcinoma and squamous cell carcinoma were similar (13.10% vs. 12.61%), while small cell carcinoma accounted for 66.67%. Among moderately differentiated patients with negative PD-L1 expression, the proportion of adenocarcinoma was significantly higher than that of squamous cell carcinoma and small cell carcinoma (47.11% vs. 26.51% vs. 0.00%) (P < 0.05). Among well-differentiated patients with negative PD-L1 expression, the proportion of adenocarcinoma was significantly higher than that of squamous cell carcinoma and small cell carcinoma (61.11% vs. 29.41% vs. 0.00%) (P < 0.05). Among well-differentiated patients with low PD-L1 expression, the proportion of squamous cell carcinoma was higher than that of adenocarcinoma (52.94% vs. 38.89%) (P < 0.05). Among moderately differentiated patients with high PD-L1 expression, the proportion of squamous cell carcinoma was higher than that of adenocarcinoma (26.51% vs. 4.96%) (P < 0.05). Table 4 Comparison of PD-L1 Expression Levels by Differentiation Degree and Histological Type in Lung Cancer Patients Differentiation Degree Histological Type PD-L1 P Value Negative (n, %) Low Expression (n, %) High Expression (n, %) 0.0056 Poorly Differentiated Adenocarcinoma 19(13.10) 74(51.03) 52(35.86) Squamous Cell Carcinoma 15(12.61) 61(51.26) 43(36.13) Small Cell Carcinoma 4(66.67) 2(33.33) 0(0.00) 0.0000 Moderately Differentiated Adenocarcinoma 57(47.11) 58(47.93) 6(4.96) Squamous Cell Carcinoma 22(26.51) 39(46.99) 22(26.51) Small Cell Carcinoma 0(0.00) 0(0.00) 0(0.00) 0.0041 Well-Differentiated Adenocarcinoma 22(61.11) 14(38.89) 0(0.00) Squamous Cell Carcinoma 10(29.41) 18(52.94) 6(17.65) Small Cell Carcinoma 0(0.00) 0(0.00) 0(0.00) Total 149 266 129 3. Discussion Lung cancer is one of the leading causes of cancer-related deaths worldwide. Numerous clinical trials have shown a positive correlation between PD-L1 expression and the efficacy of immune checkpoint inhibitors in lung cancer patients[12]. This study analyzed the expression characteristics of PD-L1 in lung cancer patients with different histological types and differentiation degrees, providing a basis for clarifying the clinical value of PD-L1 in screening populations suitable for immunotherapy and guiding individualized treatment. PD-L1 expression varies in lung cancer, and this variation is associated with multiple factors. Some studies have shown that PD-L1 expression is related to gender, smoking status, histology, differentiation, tumor size, lymph node metastasis, TNM stage, and EGFR mutation[13]. The results of this study indicate that PD-L1 level and differentiation degree are related to patient gender, with male patients having higher PD-L1 expression levels and being more prone to developing poorly differentiated tumors, while PD-L1 level showed no significant difference with patient age. Several studies have reported differences in PD-L1 levels among different histological types of lung cancer. Research data show an association between adenocarcinoma and low PD-L1 expression in non-small cell lung cancer patients[13]. Another study found that the proportion of patients with TPS < 1% was higher in the non-squamous cell carcinoma subgroup compared to squamous cell carcinoma (26% vs. 19%)[14]. In the study by Liu L U et al., 59.46% of lung adenocarcinoma patients had negative PD-L1 expression, while 43.91% of lung squamous cell carcinoma patients had negative PD-L1 expression[5]. The findings of this study are consistent with the above conclusions, suggesting that PD-L1 level is correlated with histological subtype, with higher PD-L1 levels in squamous cell carcinoma patients compared to adenocarcinoma patients. PD-L1 expression is higher in squamous cell carcinoma than in adenocarcinoma at both protein and mRNA levels[5]; however, the regulatory network and specific molecular mechanisms have not been reported. PD-L1 expression is regulated by multiple signaling molecules, such as MAPKs[15], the STAT family[16], IRF-1[17], and PIK3[18]. Whether and how PD-L1 is regulated by these molecules in squamous cell carcinoma requires further investigation. The study by Liu L U et al. indicated that PD-L1 expression is related to the differentiation degree of lung cancer, with particularly well-to-moderately differentiated patients having a 76.0% to 78.4% probability of negative PD-L1 expression[5]. This result is similar to the present study, also suggesting a negative correlation between PD-L1 level and differentiation degree, with lower PD-L1 levels in well-differentiated patients compared to poorly differentiated patients. Additionally, patient age in this study was negatively correlated with differentiation degree, with patients > 60 years old more likely to develop poorly differentiated tumors, suggesting that patient age may also be a factor in poor differentiation of lung cancer. This study confirms that PD-L1 expression in lung cancer has significant histological and differentiation degree dependencies. PD-L1 expression is significantly higher in squamous cell carcinoma patients than in adenocarcinoma patients, suggesting that squamous cell carcinoma patients may benefit more from PD-1/PD-L1 inhibitor therapy. Furthermore, PD-L1 expression is negatively correlated with differentiation degree, with a significantly increased proportion of high PD-L1 expression in poorly differentiated tumors, which may be related to enhanced tumor immune escape. The sample size of small cell lung cancer in this study is small, but preliminary results show generally low PD-L1 expression, all of which were poorly differentiated, consistent with its highly malignant biological behavior. Studies have shown that PD-L1 expression rates in small cell lung cancer patients vary across different studies[7–9,19–20]; such differences may be due to technical variations or limitations of the methods used. Future large-scale, multicenter studies are needed for further validation. The findings of this study suggest that in clinical immunotherapy decision-making, the histological type and differentiation degree of lung cancer should be comprehensively considered, combined with PD-L1 expression levels, to guide individualized treatment selection. Particularly for well-differentiated adenocarcinoma patients, the higher proportion of PD-L1 negativity may indicate limited response to immunotherapy monotherapy, necessitating exploration of combination therapy strategies. 4. Conclusion PD-L1 expression exhibits significant histological and differentiation degree heterogeneity in lung cancer. Higher PD-L1 expression in squamous cell carcinoma and poorly differentiated tumors suggests that these patients may be potential candidates for immunotherapy. This study provides important reference for the selection of pathological biomarkers in lung cancer immunotherapy. Abbreviations SCLC: Small Cell Lung Cancer; PD-L1: Programmed Death-Ligand 1; IHC: Immunohistochemistry; TPS: Tumor Proportion Score; OS: Overall Survival. SCC :Squamous cell carcinoma.ADC:adenocarcinoma Declarations Ethics Approval and Consent to Participate This study was conducted in accordance with the Declaration of Helsinki (as revised in 2013) and was approved by the Ethics Committee of Ningbo Clinical Pathology Diagnosis Center (Approval No. NBPCSY-251203 and date of 2025/12/19). Written informed consent was obtained from all individual participants included in the study. Consent for Publication Not applicable. Availability of Data and Materials The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Competing Interests The authors declare that they have no competing interests. Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Authors’ Contributions Xincheng Zhou: Conceptualization, Formal analysis, Investigation, Data Curation, Writing – Original Draft. Shuang Ao: Investigation, Resources, Validation, Data Curation. Yanan Guo: Methodology, Software, Validation, Formal analysis, Visualization. Jing Jin: Supervision, Project administration, Writing – Review & Editing, Funding acquisition. Acknowledgements Not applicable. References Herbst R S, Baas P, Kim D W, et al. Pembrolizumab versus docetaxel for previously treated, PD-L1-positive, advanced non-small-cell lung cancer (KEYNOTE-010): a randomised controlled trial[J]. The Lancet, 2016, 387(10027): 1540-1550. Reck M, Rodríguez-Abreu D, Robinson A G, et al. Updated analysis of KEYNOTE-024: pembrolizumab versus platinum-based chemotherapy for advanced non-small-cell lung cancer with PD-L1 tumor proportion score of 50% or greater[J]. Journal of Clinical Oncology, 2019, 37(7): 537-546. Riely G J, Wood D E, Ettinger D S, et al. Non-small cell lung cancer, version 4.2024, NCCN clinical practice guidelines in oncology[J]. Journal of the National Comprehensive Cancer Network, 2024, 22(4): 249-274. Chinese Society of Clinical Oncology Guideline Working Committee. Chinese Society of Clinical Oncology (CSCO) Guidelines for the Diagnosis and Treatment of Non-Small Cell Lung Cancer 2024[M]. Beijing: People's Medical Publishing House, 2024. Liu L U, Xie B, Zhu W, et al. High expression of PD-L1 mainly occurs in non-small cell lung cancer patients with squamous cell carcinoma or poor differentiation[J]. Oncology Research, 2023, 31(3): 275. Tancoš V, Grendár M, Farkašová A, et al. Programmed death ligand 1 protein expression, histological tumour differentiation and intratumoural heterogeneity in pulmonary adenocarcinoma[J]. Pathology, 2020, 52(5): 538-545. Dolled-Filhart M, Locke D, Murphy T, et al. Development of a prototype immunohistochemistry assay to measure programmed death ligand-1 expression in tumor tissue[J]. Archives of Pathology & Laboratory Medicine, 2016, 140(11): 1259-1266. Garon E B, Rizvi N A, Hui R, et al. Pembrolizumab for the treatment of non-small-cell lung cancer[J]. New England Journal of Medicine, 2015, 372(21): 2018-2028. Yu S, Jia M, Li Y, et al. Differential expression of PD-L1 in central and peripheral and TTF1-positive and-negative small-cell lung cancer[J]. Frontiers in Medicine, 2021, 7: 621838. Liu S V, Reck M, Mansfield A S, et al. Updated overall survival and PD-L1 subgroup analysis of patients with extensive-stage small-cell lung cancer treated with atezolizumab, carboplatin, and etoposide (IMpower133)[J]. Journal of Clinical Oncology, 2021, 39(6): 619-630. WHO Classification of Tumours Editorial Board. WHO classification of tumours. Thoracic Tumours[M]. 5th ed. Lyon: IARC Press, 2021. Mok T S K, Wu Y L, Kudaba I, et al. Pembrolizumab versus chemotherapy for previously untreated, PD-L1-expressing, locally advanced or metastatic non-small-cell lung cancer (KEYNOTE-042): a randomised, open-label, controlled, phase 3 trial[J]. The Lancet, 2019, 393(10183): 1819-1830. Skov B G, Rørvig S B, Jensen T H L, et al. The prevalence of programmed death ligand-1 (PD-L1) expression in non-small cell lung cancer in an unselected, consecutive population[J]. Modern Pathology, 2020, 33(1): 109-117. Aggarwal C, Abreu D R, Felip E, et al. Prevalence of PD-L1 expression in patients with non-small cell lung cancer screened for enrollment in KEYNOTE-001,-010, and-024[J]. Annals of Oncology, 2016, 27: vi363. Atefi M, Avramis E, Lassen A, et al. Effects of MAPK and PI3K pathways on PD-L1 expression in melanoma[J]. Clinical Cancer Research, 2014, 20(13): 3446-3457. Li T, Zhang C, Zhao G, et al. IGFBP2 regulates PD-L1 expression by activating the EGFR-STAT3 signaling pathway in malignant melanoma[J]. Cancer Letters, 2020, 477: 19-30. Garcia-Diaz A, Shin D S, Moreno B H, et al. Interferon receptor signaling pathways regulating PD-L1 and PD-L2 expression[J]. Cell Reports, 2017, 19(6): 1189-1201. Gao Y, Yang J, Cai Y, et al. IFN-γ-mediated inhibition of lung cancer correlates with PD-L1 expression and is regulated by PI3K-AKT signaling[J]. International Journal of Cancer, 2018, 143(4): 931-943. Schultheis A M, Scheel A H, Ozretić L, et al. PD-L1 expression in small cell neuroendocrine carcinomas[J]. European Journal of Cancer, 2015, 51(3): 421-426. Ishii H, Azuma K, Kawahara A, et al. Significance of programmed cell death-ligand 1 expression and its association with survival in patients with small cell lung cancer[J]. Journal of Thoracic Oncology, 2015, 10(3): 426-430. 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-8753810","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":594706028,"identity":"91c71602-b78b-4dfe-a848-6d2c64c6325f","order_by":0,"name":"Xincheng Zhou","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Xincheng","middleName":"","lastName":"Zhou","suffix":""},{"id":594706029,"identity":"ec6a5fdc-8bfb-4d25-ba51-82e7ac9dcade","order_by":1,"name":"Shuang Ao","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Shuang","middleName":"","lastName":"Ao","suffix":""},{"id":594706030,"identity":"0888f97c-7675-49fa-8623-f000e36ebd03","order_by":2,"name":"Yanan Guo","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Yanan","middleName":"","lastName":"Guo","suffix":""},{"id":594706031,"identity":"1a9c8baa-7c64-402b-8595-5d5c53e04164","order_by":3,"name":"Jing Jin","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAvklEQVRIiWNgGAWjYBACNvnznx8k8EjI8ROthU+Cwczgg4yFsWQDsVrkJBgMJGfYVCRuOEC0w6QbEox5ciQSNx9P3sDwo2IbEVpkDhx4zHNGwnjbmWcFjD1nbhOhhSGxwZi3R0J2240cA2bGNqK0JDNI8/6TYNw8g2gtEmkMkjN4JBQ3SBCthecMm8EHHgljCaBfDhLlF/n2HmZgVNbJ8bcnb3zwo4IILUggweAASerBWkjVMQpGwSgYBSMEAABm2zlGWHXXEgAAAABJRU5ErkJggg==","orcid":"","institution":"","correspondingAuthor":true,"prefix":"","firstName":"Jing","middleName":"","lastName":"Jin","suffix":""}],"badges":[],"createdAt":"2026-02-01 05:23:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8753810/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8753810/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":103260016,"identity":"1d05eb41-1479-410e-9710-4b7d68521809","added_by":"auto","created_at":"2026-02-23 17:41:37","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":802600,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8753810/v1/1d665529-d181-45ea-8aec-0337fd7e0a64.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Expression Differences and Clinical Significance of PD-L1 in Lung Cancer Patients with Different Histological Types and Differentiation Degrees","fulltext":[{"header":"Introduction","content":"\u003cp\u003eProgrammed death ligand 1 (PD-L1) is currently the most extensively studied inhibitory immune checkpoint molecule, and its expression level has become one of the primary biomarkers for predicting the efficacy of immunotherapy in lung cancer patients. Numerous large-scale clinical trials have shown that patients with high PD-L1 expression respond better to PD-1/PD-L1 inhibitor therapy[1\u0026ndash;2]. Both NCCN and CSCO guidelines explicitly recommend different immunotherapy strategies based on the immunohistochemical expression level of PD-L1 in lung cancer patients[3\u0026ndash;4]. However, PD-L1 expression in lung cancer is highly heterogeneous, and its expression patterns across different histological types and differentiation degrees require further clarification.\u003c/p\u003e \u003cp\u003eExisting studies suggest that PD-L1 expression is higher in lung squamous cell carcinoma than in lung adenocarcinoma[5], and differentiation degree may be negatively correlated with PD-L1 expression[6]. Data on PD-L1 expression in small cell lung cancer remain controversial[7\u0026ndash;9], and its clinical significance warrants further investigation. Immune checkpoint inhibitors targeting PD-1/PD-L1 have shown clinical activity in small cell lung cancer treatment[10]. This study retrospectively analyzed PD-L1 expression data from 544 lung cancer patients to systematically evaluate its relationship with histological type and differentiation degree, aiming to provide pathological evidence for individualized immunotherapy strategies in lung cancer.\u003c/p\u003e"},{"header":"1. Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e1.1 General Information\u003c/h2\u003e \u003cp\u003eA total of 544 patients diagnosed with lung cancer at Ningbo Pathological Diagnosis Center from August 2023 to March 2024 were selected as the study subjects. Among them, 134 were female and 410 were male; 139 were \u0026le;\u0026thinsp;60 years old and 405 were \u0026gt;\u0026thinsp;60 years old. Histological types included 302 cases of adenocarcinoma, 236 cases of squamous cell carcinoma, and 6 cases of small cell carcinoma. Differentiation degrees were classified as 270 poorly differentiated, 204 moderately differentiated, and 70 well-differentiated cases.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e1.2 Inclusion and Exclusion Criteria\u003c/h2\u003e \u003cp\u003eInclusion criteria: ① Age 18\u0026ndash;90 years; ② Signed informed consent; ③ Pathologically confirmed diagnosis of lung cancer; ④ Complete PD-L1 immunohistochemical test results available.\u003c/p\u003e \u003cp\u003eExclusion criteria: ① Pathological diagnosis other than lung cancer; ② No PD-L1 test results; ③ Incomplete clinical data.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e1.3 Detection Methods\u003c/h2\u003e \u003cp\u003ePD-L1 expression was detected using immunohistochemistry with PD-L1 antibody (clone 22C3). Tumor proportion score (TPS) was used as the expression standard: TPS\u0026thinsp;\u0026lt;\u0026thinsp;1% was considered negative, 1%\u0026ndash;49% as low expression, and \u0026ge;\u0026thinsp;50% as high expression. Differentiation degree was graded according to the WHO Classification of Thoracic Tumours (5th edition)[11].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e1.4 Statistical Methods\u003c/h2\u003e \u003cp\u003eStatistical analysis was performed using SPSS 26.0 software. PD-L1 IHC results (TPS\u0026thinsp;\u0026lt;\u0026thinsp;1%, 1%\u0026ndash;49%, \u0026ge;\u0026thinsp;50%) were assigned values of 0, 1, and 2, respectively. Chi-square test was used to analyze whether there were differences in PD-L1 expression among different groups (e.g., gender, age, histological type, differentiation degree), with a P value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"2. Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Relationship Between PD-L1 Expression and Clinical Characteristics\u003c/h2\u003e \u003cp\u003ePD-L1 expression showed significant differences between genders (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), with a higher proportion of PD-L1 positivity in male patients compared to females. No significant difference in PD-L1 expression was found between age groups (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05). Differentiation degree showed significant differences in both gender and age groups (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), with a higher proportion of poorly differentiated tumors in male patients and those\u0026thinsp;\u0026gt;\u0026thinsp;60 years old.\u003c/p\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\u003eRelationship Between PD-L1 Expression and Gender/Age in Lung Cancer Patients (n\u0026thinsp;=\u0026thinsp;544)\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\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eNumber\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003ePD-L1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNegative(n, %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLow Expression(n, %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHigh\u003c/p\u003e \u003cp\u003eExpression(n, %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eP\u0026nbsp;Value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003e0.0000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e41(75.37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e94(22.93)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e203(49.51)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e11(27.56)\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\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13(24.63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e55(41.04)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e63(47.01)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e16(11.94)\u003c/p\u003e \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\u003eAge\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003e0.7075\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026le;\u0026thinsp;60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13(25.55)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35(25.18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e72(51.80)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e32(23.02)\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\"\u003e \u003cp\u003e\u0026gt;60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40(74.45)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11(28.15)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e194(47.90)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e97(23.95)\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\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e544\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14(27.39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e266(48.90)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12(23.71)\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 \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Relationship Between PD-L1 Expression and Histological Type\u003c/h2\u003e \u003cp\u003eThe proportion of adenocarcinoma patients with negative PD-L1 expression was significantly higher than that of squamous cell carcinoma patients (32.45% vs. 19.92%), while the proportion of adenocarcinoma patients with high PD-L1 expression was lower than that of squamous cell carcinoma patients (19.21% vs. 30.08%) (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Small cell carcinoma patients had the highest proportion of negative PD-L1 expression (66.67%), with no cases showing high expression.\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\u003eRelationship Between PD-L1 Expression and Histological Type in Lung Cancer Patients (n\u0026thinsp;=\u0026thinsp;544)\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\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eHistological Type\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eNumber(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"4\" nameend=\"c6\" namest=\"c3\"\u003e \u003cp\u003ePD-L1\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNegative(n, %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLow Expression(n, %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHigh Expression(n, %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eP\u0026nbsp;Value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003e0.0006\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAdenocarcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30(55.51)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e98(32.45)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e146(48.34)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5(19.21)\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\"\u003e \u003cp\u003eSquamous Cell Carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23(43.38)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e47(19.92)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e118(50.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7(30.08)\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\"\u003e \u003cp\u003eSmall Cell Carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6(1.10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(66.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2(33.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(0.00)\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\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e544\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e149\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e266\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e129\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 \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e2.3 Relationship Between PD-L1 Expression and Differentiation Degree\u003c/h2\u003e \u003cp\u003eWell-differentiated patients had the highest proportion of negative PD-L1 expression (45.71%) and the lowest proportion of high PD-L1 expression (8.57%). Poorly differentiated patients showed a significantly increased proportion of high PD-L1 expression (35.98%) (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\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\u003eRelationship Between PD-L1 Expression and Differentiation Degree in Lung Cancer Patients (n\u0026thinsp;=\u0026thinsp;544)\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\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eDifferentiation Degree\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eNumber (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003ePD-L1\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNegative (n, %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLow Expression (n, %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHigh Expression (n, %)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePoorly Differentiated\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e264(48.53)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38(14.39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e137(51.89)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e95(35.98)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eModerately Differentiated\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e204(37.50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e79(38.73)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e97(47.55)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e28(13.73)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWell-Differentiated\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e70(12.87)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e32(45.71)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32(45.71)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6(8.57)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e544\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e149\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e266\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e129\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e2.4 Interrelationship Among PD-L1 Expression, Differentiation Degree, and Histological Type\u003c/h2\u003e \u003cp\u003eAmong poorly differentiated patients with negative PD-L1 expression, the proportions of adenocarcinoma and squamous cell carcinoma were similar (13.10% vs. 12.61%), while small cell carcinoma accounted for 66.67%. Among moderately differentiated patients with negative PD-L1 expression, the proportion of adenocarcinoma was significantly higher than that of squamous cell carcinoma and small cell carcinoma (47.11% vs. 26.51% vs. 0.00%) (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Among well-differentiated patients with negative PD-L1 expression, the proportion of adenocarcinoma was significantly higher than that of squamous cell carcinoma and small cell carcinoma (61.11% vs. 29.41% vs. 0.00%) (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Among well-differentiated patients with low PD-L1 expression, the proportion of squamous cell carcinoma was higher than that of adenocarcinoma (52.94% vs. 38.89%) (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Among moderately differentiated patients with high PD-L1 expression, the proportion of squamous cell carcinoma was higher than that of adenocarcinoma (26.51% vs. 4.96%) (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of PD-L1 Expression Levels by Differentiation Degree and Histological Type in Lung Cancer Patients\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\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eDifferentiation Degree\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eHistological Type\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003ePD-L1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eP\u0026nbsp;Value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNegative (n, %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLow Expression (n, %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHigh Expression (n, %)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003e0.0056\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003ePoorly Differentiated\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAdenocarcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19(13.10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e74(51.03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e52(35.86)\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=\"c2\"\u003e \u003cp\u003eSquamous Cell Carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15(12.61)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e61(51.26)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e43(36.13)\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=\"c2\"\u003e \u003cp\u003eSmall Cell Carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(66.67)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2(33.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(0.00)\u003c/p\u003e \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\u003e0.0000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eModerately Differentiated\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAdenocarcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e57(47.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e58(47.93)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6(4.96)\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=\"c2\"\u003e \u003cp\u003eSquamous Cell Carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22(26.51)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e39(46.99)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e22(26.51)\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=\"c2\"\u003e \u003cp\u003eSmall Cell Carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0(0.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0(0.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(0.00)\u003c/p\u003e \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\u003e0.0041\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eWell-Differentiated\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAdenocarcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22(61.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14(38.89)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(0.00)\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=\"c2\"\u003e \u003cp\u003eSquamous Cell Carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10(29.41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e18(52.94)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6(17.65)\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=\"c2\"\u003e \u003cp\u003eSmall Cell Carcinoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0(0.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0(0.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0(0.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e149\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e266\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e129\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 \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"3. Discussion","content":"\u003cp\u003eLung cancer is one of the leading causes of cancer-related deaths worldwide. Numerous clinical trials have shown a positive correlation between PD-L1 expression and the efficacy of immune checkpoint inhibitors in lung cancer patients[12]. This study analyzed the expression characteristics of PD-L1 in lung cancer patients with different histological types and differentiation degrees, providing a basis for clarifying the clinical value of PD-L1 in screening populations suitable for immunotherapy and guiding individualized treatment.\u003c/p\u003e \u003cp\u003ePD-L1 expression varies in lung cancer, and this variation is associated with multiple factors. Some studies have shown that PD-L1 expression is related to gender, smoking status, histology, differentiation, tumor size, lymph node metastasis, TNM stage, and EGFR mutation[13]. The results of this study indicate that PD-L1 level and differentiation degree are related to patient gender, with male patients having higher PD-L1 expression levels and being more prone to developing poorly differentiated tumors, while PD-L1 level showed no significant difference with patient age.\u003c/p\u003e \u003cp\u003eSeveral studies have reported differences in PD-L1 levels among different histological types of lung cancer. Research data show an association between adenocarcinoma and low PD-L1 expression in non-small cell lung cancer patients[13]. Another study found that the proportion of patients with TPS\u0026thinsp;\u0026lt;\u0026thinsp;1% was higher in the non-squamous cell carcinoma subgroup compared to squamous cell carcinoma (26% vs. 19%)[14]. In the study by Liu L U et al., 59.46% of lung adenocarcinoma patients had negative PD-L1 expression, while 43.91% of lung squamous cell carcinoma patients had negative PD-L1 expression[5]. The findings of this study are consistent with the above conclusions, suggesting that PD-L1 level is correlated with histological subtype, with higher PD-L1 levels in squamous cell carcinoma patients compared to adenocarcinoma patients. PD-L1 expression is higher in squamous cell carcinoma than in adenocarcinoma at both protein and mRNA levels[5]; however, the regulatory network and specific molecular mechanisms have not been reported. PD-L1 expression is regulated by multiple signaling molecules, such as MAPKs[15], the STAT family[16], IRF-1[17], and PIK3[18]. Whether and how PD-L1 is regulated by these molecules in squamous cell carcinoma requires further investigation.\u003c/p\u003e \u003cp\u003eThe study by Liu L U et al. indicated that PD-L1 expression is related to the differentiation degree of lung cancer, with particularly well-to-moderately differentiated patients having a 76.0% to 78.4% probability of negative PD-L1 expression[5]. This result is similar to the present study, also suggesting a negative correlation between PD-L1 level and differentiation degree, with lower PD-L1 levels in well-differentiated patients compared to poorly differentiated patients. Additionally, patient age in this study was negatively correlated with differentiation degree, with patients\u0026thinsp;\u0026gt;\u0026thinsp;60 years old more likely to develop poorly differentiated tumors, suggesting that patient age may also be a factor in poor differentiation of lung cancer.\u003c/p\u003e \u003cp\u003eThis study confirms that PD-L1 expression in lung cancer has significant histological and differentiation degree dependencies. PD-L1 expression is significantly higher in squamous cell carcinoma patients than in adenocarcinoma patients, suggesting that squamous cell carcinoma patients may benefit more from PD-1/PD-L1 inhibitor therapy. Furthermore, PD-L1 expression is negatively correlated with differentiation degree, with a significantly increased proportion of high PD-L1 expression in poorly differentiated tumors, which may be related to enhanced tumor immune escape.\u003c/p\u003e \u003cp\u003eThe sample size of small cell lung cancer in this study is small, but preliminary results show generally low PD-L1 expression, all of which were poorly differentiated, consistent with its highly malignant biological behavior. Studies have shown that PD-L1 expression rates in small cell lung cancer patients vary across different studies[7\u0026ndash;9,19\u0026ndash;20]; such differences may be due to technical variations or limitations of the methods used. Future large-scale, multicenter studies are needed for further validation.\u003c/p\u003e \u003cp\u003eThe findings of this study suggest that in clinical immunotherapy decision-making, the histological type and differentiation degree of lung cancer should be comprehensively considered, combined with PD-L1 expression levels, to guide individualized treatment selection. Particularly for well-differentiated adenocarcinoma patients, the higher proportion of PD-L1 negativity may indicate limited response to immunotherapy monotherapy, necessitating exploration of combination therapy strategies.\u003c/p\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003ePD-L1 expression exhibits significant histological and differentiation degree heterogeneity in lung cancer. Higher PD-L1 expression in squamous cell carcinoma and poorly differentiated tumors suggests that these patients may be potential candidates for immunotherapy. This study provides important reference for the selection of pathological biomarkers in lung cancer immunotherapy.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eSCLC: Small Cell Lung Cancer; PD-L1: Programmed Death-Ligand 1; IHC: Immunohistochemistry; TPS: Tumor Proportion Score; OS: Overall Survival. SCC :Squamous cell carcinoma.ADC:adenocarcinoma\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics Approval and Consent to Participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was conducted in accordance with the Declaration of Helsinki (as revised in 2013) and was approved by the Ethics Committee of Ningbo Clinical Pathology Diagnosis Center (Approval No. NBPCSY-251203 and date of 2025/12/19). Written informed consent was obtained from all individual participants included in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for Publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of Data and Materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eXincheng Zhou: Conceptualization, Formal analysis, Investigation, Data Curation, Writing\u0026nbsp;\u0026ndash;\u0026nbsp;Original Draft. Shuang Ao: Investigation, Resources, Validation, Data Curation. Yanan Guo: Methodology, Software, Validation, Formal analysis, Visualization. Jing Jin: Supervision, Project administration, Writing\u0026nbsp;\u0026ndash;\u0026nbsp;Review \u0026amp; Editing, Funding acquisition.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eHerbst R S, Baas P, Kim D W, et al. Pembrolizumab versus docetaxel for previously treated, PD-L1-positive, advanced non-small-cell lung cancer (KEYNOTE-010): a randomised controlled trial[J]. The Lancet, 2016, 387(10027): 1540-1550.\u003c/li\u003e\n\u003cli\u003eReck M, Rodr\u0026iacute;guez-Abreu D, Robinson A G, et al. Updated analysis of KEYNOTE-024: pembrolizumab versus platinum-based chemotherapy for advanced non-small-cell lung cancer with PD-L1 tumor proportion score of 50% or greater[J]. Journal of Clinical Oncology, 2019, 37(7): 537-546.\u003c/li\u003e\n\u003cli\u003eRiely G J, Wood D E, Ettinger D S, et al. Non-small cell lung cancer, version 4.2024, NCCN clinical practice guidelines in oncology[J]. Journal of the National Comprehensive Cancer Network, 2024, 22(4): 249-274.\u003c/li\u003e\n\u003cli\u003eChinese Society of Clinical Oncology Guideline Working Committee. Chinese Society of Clinical Oncology (CSCO) Guidelines for the Diagnosis and Treatment of Non-Small Cell Lung Cancer 2024[M]. Beijing: People\u0026apos;s Medical Publishing House, 2024.\u003c/li\u003e\n\u003cli\u003eLiu L U, Xie B, Zhu W, et al. High expression of PD-L1 mainly occurs in non-small cell lung cancer patients with squamous cell carcinoma or poor differentiation[J]. Oncology Research, 2023, 31(3): 275.\u003c/li\u003e\n\u003cli\u003eTanco\u0026scaron; V, Grend\u0026aacute;r M, Farka\u0026scaron;ov\u0026aacute; A, et al. Programmed death ligand 1 protein expression, histological tumour differentiation and intratumoural heterogeneity in pulmonary adenocarcinoma[J]. Pathology, 2020, 52(5): 538-545.\u003c/li\u003e\n\u003cli\u003eDolled-Filhart M, Locke D, Murphy T, et al. Development of a prototype immunohistochemistry assay to measure programmed death ligand-1 expression in tumor tissue[J]. Archives of Pathology \u0026amp; Laboratory Medicine, 2016, 140(11): 1259-1266.\u003c/li\u003e\n\u003cli\u003eGaron E B, Rizvi N A, Hui R, et al. Pembrolizumab for the treatment of non-small-cell lung cancer[J]. New England Journal of Medicine, 2015, 372(21): 2018-2028.\u003c/li\u003e\n\u003cli\u003eYu S, Jia M, Li Y, et al. Differential expression of PD-L1 in central and peripheral and TTF1-positive and-negative small-cell lung cancer[J]. Frontiers in Medicine, 2021, 7: 621838.\u003c/li\u003e\n\u003cli\u003eLiu S V, Reck M, Mansfield A S, et al. Updated overall survival and PD-L1 subgroup analysis of patients with extensive-stage small-cell lung cancer treated with atezolizumab, carboplatin, and etoposide (IMpower133)[J]. Journal of Clinical Oncology, 2021, 39(6): 619-630.\u003c/li\u003e\n\u003cli\u003eWHO Classification of Tumours Editorial Board. WHO classification of tumours. Thoracic Tumours[M]. 5th ed. Lyon: IARC Press, 2021.\u003c/li\u003e\n\u003cli\u003eMok T S K, Wu Y L, Kudaba I, et al. Pembrolizumab versus chemotherapy for previously untreated, PD-L1-expressing, locally advanced or metastatic non-small-cell lung cancer (KEYNOTE-042): a randomised, open-label, controlled, phase 3 trial[J]. The Lancet, 2019, 393(10183): 1819-1830.\u003c/li\u003e\n\u003cli\u003eSkov B G, R\u0026oslash;rvig S B, Jensen T H L, et al. The prevalence of programmed death ligand-1 (PD-L1) expression in non-small cell lung cancer in an unselected, consecutive population[J]. Modern Pathology, 2020, 33(1): 109-117.\u003c/li\u003e\n\u003cli\u003eAggarwal C, Abreu D R, Felip E, et al. Prevalence of PD-L1 expression in patients with non-small cell lung cancer screened for enrollment in KEYNOTE-001,-010, and-024[J]. Annals of Oncology, 2016, 27: vi363.\u003c/li\u003e\n\u003cli\u003eAtefi M, Avramis E, Lassen A, et al. Effects of MAPK and PI3K pathways on PD-L1 expression in melanoma[J]. Clinical Cancer Research, 2014, 20(13): 3446-3457.\u003c/li\u003e\n\u003cli\u003eLi T, Zhang C, Zhao G, et al. IGFBP2 regulates PD-L1 expression by activating the EGFR-STAT3 signaling pathway in malignant melanoma[J]. Cancer Letters, 2020, 477: 19-30.\u003c/li\u003e\n\u003cli\u003eGarcia-Diaz A, Shin D S, Moreno B H, et al. Interferon receptor signaling pathways regulating PD-L1 and PD-L2 expression[J]. Cell Reports, 2017, 19(6): 1189-1201.\u003c/li\u003e\n\u003cli\u003eGao Y, Yang J, Cai Y, et al. IFN-\u0026gamma;-mediated inhibition of lung cancer correlates with PD-L1 expression and is regulated by PI3K-AKT signaling[J]. International Journal of Cancer, 2018, 143(4): 931-943.\u003c/li\u003e\n\u003cli\u003eSchultheis A M, Scheel A H, Ozretić L, et al. PD-L1 expression in small cell neuroendocrine carcinomas[J]. European Journal of Cancer, 2015, 51(3): 421-426.\u003c/li\u003e\n\u003cli\u003eIshii H, Azuma K, Kawahara A, et al. Significance of programmed cell death-ligand 1 expression and its association with survival in patients with small cell lung cancer[J]. Journal of Thoracic Oncology, 2015, 10(3): 426-430.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"diagnostic-pathology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"dpat","sideBox":"Learn more about [Diagnostic Pathology](http://diagnosticpathology.biomedcentral.com)","snPcode":"13000","submissionUrl":"https://submission.nature.com/new-submission/13000/3","title":"Diagnostic Pathology","twitterHandle":"@OncoBioMed","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"PD-L1, Lung cancer, Histological type, Differentiation degree, Immunotherapy","lastPublishedDoi":"10.21203/rs.3.rs-8753810/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8753810/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjective\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo investigate the expression differences of PD-L1 in lung cancer patients with different histological types and differentiation degrees.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA retrospective analysis was conducted on the clinical data of 544 patients diagnosed with lung cancer at Ningbo Pathological Diagnosis Center. The differences in PD-L1 expression levels among different histological subtypes of lung cancer and the relationship between PD-L1 level and differentiation degree were compared.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere was a statistically significant difference in PD-L1 level between genders (P \u0026lt; 0.001), but no significant difference was found among different age groups (P \u0026gt; 0.05). No significant differences in histological types were observed between genders or age groups (P \u0026gt; 0.05). However, differentiation degrees showed significant differences between genders and age groups (P \u0026lt; 0.001). The proportion of adenocarcinoma patients with negative PD-L1 expression was significantly higher than that of squamous cell carcinoma patients (32.45% vs. 19.92%), while the proportions of adenocarcinoma patients with low and high PD-L1 expression were lower than those of squamous cell carcinoma patients (48.34% vs. 50.00%; 19.21% vs. 30.08%) (P \u0026lt; 0.001). The proportion of well-differentiated patients with negative PD-L1 expression was significantly higher than that of moderately and poorly differentiated patients (45.71% vs. 38.73% vs. 14.39%), and the proportion of well-differentiated patients with high PD-L1 expression was significantly lower than that of moderately and poorly differentiated patients (8.57% vs. 13.73% vs. 35.98%) (P \u0026lt; 0.001). Among well-differentiated patients with negative PD-L1 expression, the proportion of adenocarcinoma was significantly higher than that of squamous cell carcinoma and small cell carcinoma (61.11% vs. 29.41% vs. 0.00%) (P \u0026lt; 0.05). Among well-differentiated patients with low PD-L1 expression, the proportion of squamous cell carcinoma was higher than that of adenocarcinoma and small cell carcinoma (52.94% vs. 38.89% vs. 0.00%) (P \u0026lt; 0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePD-L1 level is correlated with histological subtype, with higher PD-L1 levels in squamous cell carcinoma patients compared to adenocarcinoma patients. PD-L1 level is also correlated with differentiation degree, with lower PD-L1 levels in well-differentiated patients compared to poorly differentiated patients. Both PD-L1 level and differentiation degree in small cell lung cancer patients are lower than those in adenocarcinoma and squamous cell carcinoma patients.\u003c/p\u003e\n\u003cp\u003eChinese Library Classification Number: R737.1\u003cbr\u003e\nDocument Identification Code: A\u003c/p\u003e","manuscriptTitle":"Expression Differences and Clinical Significance of PD-L1 in Lung Cancer Patients with Different Histological Types and Differentiation Degrees","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-23 17:41:28","doi":"10.21203/rs.3.rs-8753810/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-03T21:14:52+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-03T07:14:24+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-27T00:29:37+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"76495330615059450922382578965587110196","date":"2026-02-20T12:44:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"11229912352535219770549798879361229237","date":"2026-02-19T15:25:26+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-19T01:19:39+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-18T14:39:20+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-17T09:55:55+00:00","index":"","fulltext":""},{"type":"submitted","content":"Diagnostic Pathology","date":"2026-02-12T12:13:59+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"diagnostic-pathology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"dpat","sideBox":"Learn more about [Diagnostic Pathology](http://diagnosticpathology.biomedcentral.com)","snPcode":"13000","submissionUrl":"https://submission.nature.com/new-submission/13000/3","title":"Diagnostic Pathology","twitterHandle":"@OncoBioMed","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f53ca379-5401-4070-94e9-99ab270884a3","owner":[],"postedDate":"February 23rd, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-03T15:08:13+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-23 17:41:28","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8753810","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8753810","identity":"rs-8753810","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}