Survival After Adjuvant Radiation in Localized Small Cell Lung Cancer Treated with Complete Resection

Abstract Objectives To determine if there is an overall survival (OS) benefit to the addition of thoracic radiation therapy (RT) following R0 resection of pathologic (p) T1/2N0M0 SCLC. Methods Using the National Cancer Database, we performed a retrospective cohort analysis. Patients who underwent R0 resection for pT1/2N0M0 SCLC, stratified by receipt of adjuvant thoracic RT, were compared on the basis of OS using hierarchical Cox Proportional hazards models. Results Of 4,969 patients diagnosed with pT1/2N0M0 SCLC from 2004-2014, 1617 (33%) underwent R0 resection of their primary tumor; of these resected patients, 146 (9.0%) had adjuvant thoracic RT. In unadjusted analysis, there was no significant difference in OS between groups (Median survival: surgery alone=62.2 months vs surgery+RT=43.8 months; p=0.1436). In multivariable analysis, RT was not associated with improved survival (p=0.099). There was no significant difference in unadjusted or adjusted survival associated with receipt of radiation therapy in both a young and healthy cohort (p=0.647 for unadjusted and p=0.858 for adjusted) and a matched cohort (p=0.867; p=0.954). In the matched cohort, improved OS was associated with younger patient age (aHR=1.07, 1.04-1.10; p Conclusions Though complete resection was accomplished in a minority of patients, for these patients, survival was good. The addition of thoracic radiation therapy to complete resection does not appear to confer additional survival benefit.