Abstract 6465: A population-based analysis of brain metastasis burden and management in 8705 small cell lung cancer patients

Abstract Introduction: Patients with small cell lung cancer (SCLC) have historically been characterized by poor overall survival (OS) and high risk for brain metastases (BM), but large-scale real-world evidence on clinical presentation and treatment in this population is lacking. Methods: The aim of this study was to describe the clinical characteristics and outcomes of patients with SCLC and BM in Ontario, Canada. This retrospective cohort study included all patients in Ontario, Canada, who were diagnosed with SCLC between April 2010 and March 2018. Data were analyzed between June 2022 and July 2023. Kaplan-Meier and multivariable Cox regression analyses were performed to compare overall survival (OS) between patient cohorts stratified by disease stage, BM diagnosis, or first-line intracranial treatment modality. Results: 8705 patients were included. Median age at diagnosis was 68 years (range 18-103). Median OS of all patients was 7.46 months (95% confidence interval, CI, 7.23-7.69). 32% (n=2686) of patients developed BM (synchronous, 43.7%; asynchronous, 56.3%) and had median OS of 9.76 months (95% CI, 9.36-10.22). 102, 1654, and 880 patients received stereotactic radiosurgery (SRS), whole brain radiation therapy (WBRT), and no treatment, respectively, for their BM in the first-line setting or after prophylactic cranial irradiation (PCI). In propensity score-matched analyses, OS was equivocal between SRS- and WBRT-treated cohorts among patients who did not receive PCI (hazard ratio, HR, 1.18, 95% CI, 0.75-1.81) and those who received PCI prior to BM development (HR, 0.77, 95% CI, 0.53-1.13). Conclusions: Survival for patients with SCLC remains poor, and many patients present with BMs. With careful selection, patients with SCLC may benefit from SRS treatment. Citation Format: Karolina Gaebe, Anders W. Erickson, Sarah Chen, Arjun Sahgal, Benjamin H. Lok, Kelvin K. Chan, Sunit Das. A population-based analysis of brain metastasis burden and management in 8705 small cell lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6465.