Variations in Initiation Dates of Chemotherapy and Radiation Therapy for Definitive Management of Inoperable Non–Small Cell Lung Cancer Are Associated With Decreases in Overall Survival

Abstract

BackgroundWe evaluated trends in administration of concurrent chemoradiation therapy (CRT) and how variations in start dates of chemotherapy and radiotherapy affected overall survival (OS) in patients with non–small cell lung cancer (NSCLC) undergoing a course of definitive CRT. Materials and MethodsCases of NSCLC treated with definitive CRT were obtained from the National Cancer Database. A survival analysis was performed with Kaplan-Meier curves and Cox proportional hazards models. Propensity score matching was conducted. ResultsOn a national level, only 48.6% of patients began concurrent CRT on the same day. In a propensity-matched population, starting CRT within 6 days was associated with improved OS (17.9 months) compared with starting 7 to 13 days apart (16.5 months; P = .04). Starting dual therapy within 6 days of each other was associated with a 7% reduction in the risk of death (hazard ratio, 0.93; P = .05). Furthermore, in a propensity-matched cohort, starting CRT within 3 days was associated with longer survival (18.7 months) compared with 4 to 6 days apart (17.5 months; P = .02). Starting treatment 4 to 6 days apart was associated with an 8% increased risk of death (hazard ratio, 1.08; P = .04). ConclusionA large proportion (48.6%) of patients with unresectable NSCLC do not initiate CRT on the same day as is considered standard by national guidelines. In this population, nonsimultaneous initiation of CRT was associated with differences in OS. Further efforts to understand the mitigating factors and barriers that interfere with timely delivery of concurrent CRT are needed.