A Study on the Efficacy of Immune Checkpoint Inhibitors Combined with Chemotherapy in Patients with Oligometastatic Driver Gene-Negative Non-Small Cell Lung Cancer Undergoing Radiotherapy

Abstract Objective: Advanced NSCLC patients with negative driver genes have poor prognosis. While immune checkpoint inhibitors (ICIs) improve survival, the role of combining radiotherapy (RT) with ICIs in oligometastatic NSCLC remains unclear. This study evaluates efficacy, overall survival (OS), progression-free survival (PFS), and safety of RT- ICIs in this population. Materials and Methods: Clinical data from 160 oligometastatic NSCLC patients (negative driver genes) treated with PD-1/PD-L1 inhibitors ± platinum-based chemotherapy (Jan 2019–Jul 2024) at the first affiliated hospital of Bengbu Medical University were analyzed. Patients were grouped into RT (n=103) and Non-RT (n=57) based on metastatic NSCLC radiotherapy. Analysis survival outcomes, and Cox regression models identified independent risk factors. Subgroup analysis explored potential RT benefit populations. Results: Median follow-up was 37.6 months. RT group showed significantly improved mPFS (20.1 vs. 11.8 months, P=0.016) and mOS (32.3 vs. 16.6 months, P=0.005) compared to Non-RT. Multivariate analysis identified T-stage as a PFS risk factor, while RT was protective for PFS and OS (P<0.05). TN-stage impacted OS prognosis. Subgroup analysis revealed enhanced OS with RT in specific subgroups: male, elderly (>60 years), smokers, patients with underlying diseases, adenocarcinoma, synchronous metastasis, and advanced N-stage (P<0.05). Conclusion: RT combined with ICI significantly enhances PFS and OS in oligometastatic NSCLC patients with negative driver genes. T stage and RT are independent predictors for PFS, while TN stage and RT are predictors for OS. RT-ICI may be particularly beneficial for male, elderly, smoking, adenocarcinoma, and advanced N stage patients.