Endoscopic insights into digestive-related adverse effects of immune checkpoint inhibitors: A narrative review.

Treatment with immune checkpoint inhibitors (ICIs) is an innovative therapy for managing certain types of malignancy and has the potential to improve overall patient survival significantly. The most widely used ICIs selectively target different receptors comprising programmed cell death-1 receptor, programmed cell death-ligand 1 receptor, and cytotoxic T lymphocyte antigen 4 receptor. The widespread utilization of ICIs over the past several years, however, is frequently accompanied by immune-related adverse events (irAEs) that substantially impact the patient's quality of life, particularly those affecting the digestive system, including both the upper and lower gastrointestinal tract. Based on a literature search covering databases such as PubMed, Web of Science, Embase, and the Cochrane Library, we present an insight into primary gastrointestinal irAEs, with a special focus on endoscopic manifestations. Additionally, we analyze data regarding the pathogenetic mechanisms, diagnostic approaches, histological characteristics, and proposed therapeutic interventions for managing irAEs involving the gastrointestinal tract.