Abstract
PURPOSE: This study was designed to compare survival outcomes for non-surgically managed T1-T2N0M0 small cell lung cancer (SCLC) who received either stereotactic body radiation therapy (SBRT) or conventionally fractionated radiotherapy (CFRT) using the National Cancer Data Base (NCDB). METHODS: The was queried between 2004-2015 for patients with T1-T2N0M0 SCLC. Patients must have been treated with curative intent SBRT or CFRT (delivered daily or twice daily, 45-70 Gy) with or without chemotherapy. The primary outcome was overall survival (OS). A subset analysis of patient receiving chemotherapy was also performed. A propensity score matched (PSM) analysis was performed to compare OS among patients who received chemotherapy. RESULTS: We evaluated 1378 patients in the general cohort. Multivariable Cox regression analysis(MVA) in the general cohort revealed that SBRT was significantly associated with improved survival (HR 0.68, p<0.001) along with receipt of chemotherapy (HR 0.63, p <0.001). SBRT patients were less likely to receive chemotherapy compared to CFRT patients (p<0.01). In the chemotherapy subset, of 1096 patients, on MVA, there was a trend in favor of the SBRT group (HR 0.73; p=0.06). A 3:1 PSM analysis on the chemotherapy subset found similar results on MVA with a trend in favor of SBRT (p=0.06). CONCLUSION: Patients with T1-2N0M0 SCLC treated with SBRT regimens incorporating chemotherapy had comparable outcomes to concurrent chemoradiotherapy using standard fractionation. Treatment paradigms for T1-2N0M0 SCLC incorporating SBRT warrant further exploration and should incorporate chemotherapy.