Efficacy and safety of induction chemoimmunotherapy in older patients with unresectable stage III NSCLC: a real-world multicenter study

Background: The benefit of adding immunotherapy to induction chemotherapy before definitive chemoradiotherapy (CRT) in older patients with unresectable stage III non-small-cell lung cancer (NSCLC) remains unclear. Objectives: This real-world study aimed to evaluate the efficacy and safety of induction chemoimmunotherapy followed by CRT in this patient population. Design: A real-world multicenter study. Methods: In this retrospective, multicenter study, we enrolled patients aged ⩾65 years with unresectable stage III NSCLC who received CRT between January 2014 and June 2024. Patients were stratified into two groups: the induction chemoimmunotherapy group (I-CRT), who received PD-1/PD-L1 inhibitors plus chemotherapy before CRT, and the control group (Non-I-CRT), who received CRT without any prior immunotherapy. Propensity score matching (PSM) was used to balance baseline characteristics. The primary endpoints were progression-free survival (PFS) and overall survival (OS). Results: Among 260 patients, 141 received I-CRT and 119 constituted the Non-I-CRT control group. After 1:1 PSM (97 patients per group), the I-CRT group showed significantly improved outcomes compared to the Non-I-CRT group: median PFS was 23.4 versus 11.6 months ( p < 0.001), and median OS was 46.0 versus 24.4 months ( p = 0.009). The incidence of Grade 3/4 adverse events was comparable between the matched groups (20.6% vs 28.9%, p = 0.52). Conclusion: Induction chemoimmunotherapy before CRT is feasible in selected older NSCLC patients, offering survival benefits without significant safety concerns.