Digestive System Toxicities of Immune Checkpoint Inhibitors: Mechanisms and Clinical Implications

Immune checkpoint inhibitors (ICIs) have achieved remarkable efficacy in treating malignancies but may simultaneously induce immune-related adverse events (irAEs), among which ICI-related digestive system adverse events (ir-DSAEs) occur with relatively high frequency and present severe clinical manifestations. This review systematically examined ir-DSAEs, including clinical presentations, pathogenic mechanisms, risk factors, diagnostic approaches, and therapeutic strategies. It has been reported that ir-DSAEs primarily include colitis, hepatitis, and pancreatitis with underlying mechanisms involving T cell-mediated inflammatory responses, cytokine storm, activation of autoimmune reactions, and alterations in gut microbiota. The diagnosis of ir-DSAEs requires integration of multiple approaches. Standardized therapeutic strategies include treatment regimen adjustments, corticosteroid administration, use of selective immunosuppressants, and comprehensive supportive care. An in-depth understanding of ir-DSAEs has significant clinical implications for enhancing the safety and efficacy of ICI therapy, thereby providing a theoretical foundation for future precise prediction, prevention, and treatment of ir-DSAEs.