Abstract
BACKGROUND: Several studies have demonstrated the synergistic effects of immunotherapy and radiotherapy for both local and abscopal tumor control. However, data regarding the use of first-line immunochemotherapy (ICT) combined with radiotherapy for advanced non-small cell lung cancer (NSCLC) remain limited. This study investigated the efficacy and safety of first-line immunochemotherapy combined with radiotherapy (ICRT) and those of ICT alone. METHODS: Patients with advanced NSCLC who received first-line anti-programmed cell death protein 1 (PD-1) immunotherapy plus chemotherapy at Wuhan Union Hospital and Hunan Cancer Hospital between October 2017 and July 2021 were retrospectively analyzed. The objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety associated with treatment were assessed. Survival outcomes were analyzed using the Kaplan-Meier method. RESULTS: A total of 194 patients were included: 92 were treated with ICRT and 102 were treated with ICT. The ORRs of the ICRT and ICT groups were 57.6% and 47.1%, respectively. Patients in the ICRT group had significantly longer PFS (median: 14.9 vs. 11.5 months; P = 0.035) and OS (median: 41.3 vs. 23.1 months; P = 0.047) than those of patients in the ICT group. Patients treated with thoracic radiotherapy, those treated with extrathoracic metastasis radiotherapy, and those treated without radiotherapy had median PFS of 21.5 months, 12.9 months, and 11.5 months (P = 0.031); and median OS was not reached, 41.3 months, and 23.1 months (P = 0.007), respectively. ICRT and ICT were generally well-tolerated, and the overall incidence of adverse events was similar between the groups. A total of 2.2% (2/92) of patients experienced grade 3 or grade 4 radiation-related adverse events. CONCLUSIONS: Radiotherapy is safe and manageable when added to first-line anti-PD-1 immunotherapy and chemotherapy for patients with advanced NSCLC.