Prognostic factors and survival outcomes in older adults with extensive-stage small cell lung cancer: A multicenter retrospective cohort study.

Extensive-stage small cell lung cancer (ES-SCLC) in older adults is associated with poor outcomes, and optimal management in this population remains challenging. This study aimed to identify clinical and treatment-related factors associated with survival in patients aged ≥70 years with ES-SCLC. A retrospective multicenter cohort study included 135 older adults (aged ≥70 years) diagnosed with ES-SCLC across 3 tertiary centers. All patients received at least 1 cycle of platinum-etoposide-based chemotherapy. Demographic, clinical, and treatment variables - including metastatic sites, number of chemotherapy cycles, thoracic radiotherapy (TRT), prophylactic cranial irradiation, and palliative radiotherapy to extracranial metastases - were collected. Survival outcomes were estimated using the Kaplan-Meier method and compared using the log-rank test. Prognostic factors for progression-free survival and overall survival (OS) were evaluated using Cox proportional hazards regression models. The median age was 73.2 years; 88.1% of patients were male. The objective response rate was 69.9%. Median progression-free survival and OS were 7.1 and 8.3 months, respectively (95% CI: 6.09-8.17 and 7.67-8.93). In multivariate analysis, Eastern Cooperative Oncology Group performance status ≥2 (P <.001), liver metastases (P = .006), fewer than 4 chemotherapy cycles (P <.001), absence of prophylactic cranial irradiation (P = .028), and lack of palliative radiotherapy to extracranial metastases (P <.001) were independently associated with shorter OS. TRT did not retain statistical significance in multivariate analysis. Only 34.1% of patients received second-line therapy. The 1-year and 2-year OS rates were 33% and 12%, respectively. Fit older adults (Eastern Cooperative Oncology Group performance status 0-1) may derive meaningful survival benefit from multimodal treatment strategies. Treatment decisions should be individualized based on functional status rather than chronological age alone. Prospective studies incorporating comprehensive geriatric assessment are warranted.