Association between immune-related adverse events and treatment efficacy in patients with oral squamous cell carcinoma receiving immune checkpoint inhibitors

This retrospective study examined the relationship between the efficacy of immune checkpoint inhibitors (ICIs) and immune-related adverse events (irAEs) in patients with recurrent or metastatic oral squamous cell carcinoma (OSCC). Forty patients who received ICIs as their initial treatment were included in the analysis, which utilized medical records. The severity of irAEs was evaluated according to the Common Terminology Criteria for Adverse Events version 5.0. Treatment outcomes were evaluated based on the overall response rate (ORR), disease control rate (DCR), overall survival (OS), and progression-free survival (PFS). Twenty-two irAEs were observed in 15 patients, after a median follow-up period of 15.5 months. Treatment response was significantly higher in irAE+ patients for ORR (66.7 %) and DCR (93.3 %) compared to irAE- patients (28.0 %, 48.0 %). The median OS was 36 months for irAE+ patients and 12 months for irAE- patients ( P < 0.01). Similarly, the median PFS was 10 months for irAE+ patients and 2 months for irAE- patients ( P < 0.05). Multivariate analysis identified irAE occurrence (hazard ratio [HR]: 0.3; 95 % confidence interval [CI]: 0.07–0.9; P < 0.05) as independent factors for prolonged OS. These results revealed a significant correlation between irAE occurrence and improved clinical outcomes. IrAEs could potentially serve as biomarkers for predicting ICI efficacy in patients with OSCC.