The Role of Immune-Related Adverse Events in Prognosis and Efficacy Prediction for Patients with Non-Small Cell Lung Cancer Treated with Immunotherapy: A Retrospective Clinical Analysis.

ABSTRACT

PURPOSE: The development of immune-related adverse events (irAEs) in patients undergoing immunotherapy has been reported to be a favorable prognostic factor in several studies. We aimed to examine the correlation between irAEs and prognosis in patients with non-small cell lung cancer (NSCLC) and further reveal the patient characteristics associated with response to immunotherapy among treatment responders who developed irAEs. METHODS: We retrospectively enrolled 80 patients with NSCLC who received immunotherapy at Shinshu University Hospital between February 2016 and February 2020. Progression-free survival (PFS) and overall survival (OS) were compared between patients with and those without irAEs. We examined the prognostic factors associated with PFS and OS using univariate and multivariate Cox proportional-hazards models. We further analyzed the patients who developed irAEs by classifying them into responders and non-responders. RESULTS: Twenty-five patients developed irAEs. The median PFS and OS of the patients with irAEs were significantly longer than those of the patients without irAEs (6.8 vs. 1.9 months, p < 0.001, and 37.8 vs. 8.1 months, p < 0.001, respectively). Multivariate analysis associated with PFS and OS indicated that the development of irAEs was an independent favorable prognostic factor. Among the patients developing irAEs, the responder group had a significantly higher incidence of multiple irAEs than the non-responder group (41.7 vs. 0.0%, p = 0.009). CONCLUSION: Our findings revealed that the development of irAEs was associated with clinical benefits in NSCLC patients who received immunotherapy. In particular, patients with multiple irAEs might have good prognoses.