3620 - Prognostic Impact of Supraclavicular and Contralateral Hilar Lymph Node Involvement in Limited-Stage Small Cell Lung Cancer: A Multicenter Study
Presenter(s)
J. Shan1, J. Yu1, S. Hu2, Y. Liu3, L. Zhao4, D. Yang1, X. Chang1, L. Jiang1, L. Liuhua1, Y. Teng1, D. Xin1, R. Yu1, H. Yu1, S. Ma5, and A. Shi1; 1Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China, 2Harbin Medical University Cancer Hospital, Harbin, Helongjiang, China, 3The First Department of Medical Oncology, Beidahuang Industry Group General Hospital, Harbin, China, 4Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin, China, 5Key Laboratory of Molecular Oncology, Beijing Key Laboratory of Carcinogenesis and Translational Research, Department of Thoracic Surgery I, Peking University Cancer Hospital & Institute, Beijing, China
Purpose/Objective(s): The prognostic impact of supraclavicular and/or contralateral hilar lymph node (SCV and/or CH LN) involvement in limited-stage small-cell lung cancer (LS-SCLC) remains controversial. Whether these patients have inferior survival or distinct toxicity profiles compared with those without such nodal involvement has not been well established in contemporary real-world cohorts.
Materials/Methods: We retrospectively analyzed 1,447 consecutive patients diagnosed between 2015 and 2025. After exclusion of extensive-stage disease, absence of definitive radiotherapy, and missing key data, 1,013 patients with LS-SCLC were eligible, including 388 with SCV and/or CH LN involvement and 625 without. Overall survival (OS) and progression-free survival (PFS) were compared using Kaplan–Meier analysis and multivariable Cox regression. Inverse probability of treatment weighting (IPTW) was applied to adjust for baseline imbalances. Landmark analyses at 12 and 24 months were performed to mitigate guarantee-time bias. Adverse events (AEs) were graded according to CTCAE criteria.
Results: Before weighting, SCV and/or CH LN involvement was associated with more advanced T stage and nodal burden. After IPTW adjustment, baseline characteristics were well balanced. With a median follow-up exceeding 5 years, no significant difference in OS was observed between groups (HR 1.21, 95% CI 1.00–1.46; P=0.052). In landmark analyses, survival differences remained nonsignificant at both 12 months (HR 1.04, P=0.748) and 24 months (HR 1.05, P=0.796). PFS was similarly comparable between groups (HR 1.12, 95% CI 0.95–1.32; P=0.191). Treatment-related toxicity profiles were largely similar. The incidences of grade 3–5 hematologic toxicities—including leukopenia, neutropenia, thrombocytopenia, and anemia—were comparable between cohorts. Non-hematologic toxicities such as radiation esophagitis and pneumonitis also showed no clinically meaningful differences.
Conclusion: In this large real-world LS-SCLC cohort, SCV and/or CH LN involvement was not independently associated with inferior overall survival or progression-free survival after adjustment for baseline characteristics. Toxicity profiles were comparable between groups. These findings suggest that SCV and/or CH LN involvement should not preclude definitive multimodality treatment in LS-SCLC.