Radiation Therapy is Independently Associated with Worse Survival After R0-Resection for Stage I–II Non-small Cell Lung Cancer: An Analysis of the National Cancer Data Base

Background: The 1998 post-operative radiotherapy meta-analysis for lung cancer showed a survival detriment associated with radiation for stage I–II resected non-small cell lung cancer (NSCLC), but has been criticized for including antiquated radiation techniques. We analyzed the National Cancer Database (NCDB) to determine the impact of radiation after margin-negative (R0) resection for stage I–II NSCLC on survival. Methods: Adult patients from 2004 to 2014 were analyzed from the NCDB with respect to receiving radiation as part of their first course of treatment for resected stage I–II NSCLC; the primary outcome measure was overall survival. Results: A total of 197,969 patients underwent R0 resection for stage I–II NSCLC, and 4613 received radiation. Median radiation dose was 55 Gy with a 50–60 Gy interquartile range. On adjusted analysis, treatment at a community cancer program, sublobectomy, tumor size (3–7 cm), and pN1/Nx were associated with receiving radiation (odds ratio > 1, p < 0.05). The irradiated group had shorter median survival (45.8 vs. 77.5 months, p < 0.001), and radiation was independently associated with worse overall survival (hazard ratio (HR) 1.339, 95% confidence interval (CI) 1.282–1.399). After propensity score matching, radiation remained associated with worse overall survival (HR 1.313, 95% CI 1.237–1.394, p < 0.001). Conclusions: Radiotherapy was independently associated with worse survival after R0 resection of stage I–II NSCLC in the NCDB and was more likely to be delivered in community cancer programs.