Clinical Outcomes and Prognostic Factors in Driver-Negative Stage IV Non-small Cell Lung Cancer Patients Receiving Thoracic Radiotherapy: A Single-Center Retrospective Study
Chaozhen Shang, Jiangping Yang, Miao Wang, Na Peng, Bo Yang, Guoxu Wang, Haoyu Li, Simeng Tan, Qiao Fang, Mei Yang, Yaoxiong XiaIntroduction
The role of thoracic radiotherapy (TRT) in stage IV non-small cell lung cancer (NSCLC) without targetable driver alterations remains unclear. We evaluated outcomes, prognostic factors, and safety in patients receiving TRT and systemic therapy.
Methods
In this single-center retrospective cohort study, we analyzed patients identified according to predefined criteria who received TRT and systemic therapy at a single tertiary cancer center between January 2019 and December 2023. Overall survival (OS), progression-free survival (PFS), and local control (LC) were estimated using Kaplan–Meier analysis. Conventional Cox regression constituted the primary prognostic analysis, with Firth penalized Cox regression used as a small-sample sensitivity analysis. Exploratory conditional landmark and time-dependent Cox analyses assessed potential time-related bias.
Results
Forty-eight patients were included. Median OS, PFS, and LC were 33.17 months (95% CI 19.29–47.05), 12.17 months (95% CI 8.89–15.45), and 12.47 months (95% CI 9.00–15.98), respectively. Best in-field response was partial response in 12 patients (25.0%), stable disease in 32 (66.7%), and progressive disease in 4 (8.3%). Squamous histology was consistently associated with poorer OS and PFS, whereas other multivariable associations were less stable in sensitivity analyses. Time-dependent anti-PD-1 exposure was not significantly associated with OS. Metastatic progression predominated among patients who died. In the exploratory 6-month conditional landmark analysis, TRT timing was not associated with OS or PFS. Grade 3–4 pneumonitis and esophagitis each occurred in one patient (2.1%), and no grade 5 adverse event was documented.
Conclusion
Most irradiated thoracic lesions showed partial response or stable disease at the best post-TRT assessment, while distant progression predominated among patients who died during follow-up. The prognostic findings are exploratory and require validation in larger prospective cohorts.