Outcomes of initial therapy for synchronous brain metastases from small cell lung cancer: a single-institution retrospective analysis

Small cell lung cancer (SCLC) has a propensity for brain metastases, which is associated with poor prognosis. We sought to determine predictors of overall survival (OS) and brain progression-free survival (bPFS) in SCLC patients with synchronous brain metastases at the time of initial SCLC diagnosis. A total of 107 SCLC patients with synchronous brain metastases treated at a single institution were included in this retrospective analysis. These patients had brain lesions present on initial staging imaging. Survival was estimated using the Kaplan-Meier method with log-rank test. Factors predictive of OS and bPFS were analyzed using Cox proportional hazards regression model. Median OS for the entire cohort was 9 months (interquartile range, 4.2-13.8 months) and median bPFS was 7.3 months (interquartile range, 3.5- 11.1 months). OS was 30.3% at 1 year and 14.4% at 2 years, while bPFS was 22.0% at 1 year and 6.9% at 2 years. The median number of brain lesions at diagnosis was 3 (interquartile range, 2-8), and the median size of the largest metastasis was 2.0 cm (interquartile range, 1.0-3.3 cm). Increased number of brain lesions was significantly associated with decreased OS. Patients who received both chemotherapy and whole brain radiation therapy (WBRT) had improved OS (P=0.02) and bPFS (P=0.005) compared to those who had either chemotherapy or WBRT alone. There was no significant difference in OS or bPFS depending on the sequence of therapy or the dose of WBRT. Thirteen patients underwent upfront brain metastasis resection, which was associated with improved OS (P=0.02) but not bPFS (P=0.09) compared to those who did not have surgery. The combination of chemotherapy and WBRT was associated with improved OS and bPFS compared to either modality alone. Upfront brain metastasis resection was associated with improved OS but not bPFS compared to those who did not have surgery.