Efficacy and safety of thoracic radiotherapy in metastatic non–small cell lung cancer during the immunotherapy era: A real-world study.

Abstract

e20577 Background: The synergistic effect of immunotherapy combined with thoracic radiotherapy (TRT) in locally advanced non-small cell lung cancer (NSCLC) have been confirmed. However, the potential benefits of immunotherapy combined with TRT, especially conventional fractionated thoracic radiotherapy (ConvTRT) in patients with metastatic NSCLC remain unclear. Methods: This study retrospectively evaluated patients with metastatic NSCLC who received immunotherapy with or without TRT between January 2020 and December 2024. Propensity score matching (PSM) was used to balance baseline characteristics between the ConvTRT and non-TRT groups. The effectiveness and feasibility of the combination of immunotherapy and ConvTRT were evaluated in patients with metastatic NSCLC. Results: A total of 186 patients with metastatic NSCLC were included, with a median follow-up of 22.0 months. Survival advantage was observed in the group that received any form of TRT (n = 43). After PSM, ConvTRT cohort (n=34) showed a significant survival benefit with a median overall survival (OS) of 29.80 versus 20.3 months in patients without TRT (hazard ratio [HR] 0.44, 95% CI: 0.22–0.87; P=0.016), whereas progression-free survival (PFS) did not differ significantly between both two groups (HR 0.83, 95% CI: 0.49–1.38; P=0.462). The OS benefits were most pronounced among men, ever-smokers, patients with squamous histology, and those receiving first-line immunotherapy. Conclusions: The combination of immunotherapy and ConvTRT is associated with survival benefits and may represent an effective treatment strategy for patients with metastatic NSCLC.