Impact of Liver Metastasis on First-Line Immunotherapy in Stage IV Non-Small Cell Lung Cancer

Background: Immunotherapy has become a key component of sys-temic therapy in stage IV non-small cell lung cancer (NSCLC). How-ever, there have been conflicting reports of its efficacy in patients with liver metastasis (LM).Methods: Using National Cancer Database (NCDB), patients who have been diagnosed and treated at Commission on Cancer- par-ticipating US institutions were screened for analysis. Selection criteria included clinical stage IV NSCLC, available cTNM stage information, overall survival (OS) with at least 1 month, and diag-nosis between 2015 and 2017. They were grouped based on status of LM as well as use of immunotherapy. Clinical characteristics were collected and their association with LM/immunotherapy was ana-lyzed. Impact of immunotherapy on OS was examined according to LM status. Propensity score matching (PSM) analysis was also conducted. Results: A total of 83,479 including 18,497 LM-positive and 64,982 LM-negative patients met the study criteria. Presence of LM was associated with a number of clinical variables such as younger age, male sex, and chemotherapy. OS in patients with LM was signifi-cantly worse than that in those without LM (median OS, 5.0 vs. 8.8 months; hazard ratio (HR), 1.46; log-rank, P < 0.0001). Significant OS benefit from immunotherapy was observed in both LM-positive (median OS, 4.1 vs. 9.0 months; HR, 0.62; P < 0.0001) and negative groups (median OS, 7.2 vs. 15.6 months; HR, 0.64; P < 0.0001).Conclusion: Immunotherapy benefited similarly to the survival of metastatic NSCLC patients regardless of with or without LM. Further research to validate the result would be warranted.