Background:Non-small cell lung cancer (NSCLC) with liver metastasis carries a poor prognosis, and evidence for optimal treatment strategies remains limited. The combination of radiotherapy (RT) and immunochemotherapy has shown promise in improving survival outcomes for patients with advanced NSCLC, however, large cohort studies targeting NSCLC with liver metastasis are lacking. The purpose of this study was to analyze the impact of RT combined with immunochemotherapy on the long-term survival of NSCLC patients with liver metastasis leveraging data from the Surveillance, Epidemiology, and End Results Program (SEER) database and Xinqiao Hospital in China.
Methods:Patients diagnosed with NSCLC and liver metastasis between 2010 and 2020 were screened from the SEER 17 registry. Patients were categorized into three cohorts: immunochemotherapy alone (IOC), RT + immunochemotherapy (RT + IOC) and chemotherapy + RT (CRT). Survival analysis, propensity score matching (PSM), subgroup analysis, and Cox regression were performed. The primary endpoints were overall survival (OS) and cancer-specific survival (CSS). Additionally, data from Xinqiao Hospital were used for validation.
Results:A total of 6,309 patients were enrolled, including 1,691 in the IOC cohort, 1,605 in the RT + IOC cohort, and 3,013 in the CRT cohort. The median overall survival (mOS) was significantly higher in the RT + IOC cohort compared to the IOC cohort (9 vs. 7 months, P<0.001). Similar results were observed for median cancer-specific survival (mCSS). After PSM, the survival benefits of the RT + IOC cohort persisted. Subgroup analysis revealed that most subgroups favored RT + IOC treatment. Xinqiao Hospital data further validated these findings with better median progression-free survival (mPFS) in RT + IOC cohort compared to the IOC cohort (9.3 vs. 4.1 months, P=0.03) and mOS (13.2 vs. 8.7 months, P=0.02). Furthermore, the discrepancies in survival between RT + IOC cohort and CRT cohort were compared. The SEER data revealed that the mOS and mCSS were better in RT + IOC cohort both before and after PSM. Our single-center data further validated the survival benefits of RT + IOC treatment when compared to CRT treatment.
Conclusions:The combination of radiotherapy and immunochemotherapy provides better survival benefits for NSCLC patients with liver metastasis than immunochemotherapy alone or chemotherapy + radiotherapy. Further research is necessary to explore the optimal radiotherapy methods for this patient population.
