Management of gastrointestinal adverse events induced by immune‐checkpoint inhibitors

Immune-checkpoint inhibitors (ICIs) have been proven promising for advanced cancers, and they are characterized by a unique treatment-related adverse event (AE) spectrum. Toxicity of the gastrointestinal (GI) tract is one of the most common AEs and often results in discontinuation of ICIs. Since most of the current studies have focused on the incidence, characteristics, and management of colitis, very little is known about other types of GI AEs. Herein, we review the available relevant literature on upper and lower GI toxicities, and present an algorithm for GI AE management based on the existing evidence and our clinical experience. Nausea and decreased appetite are the most common upper GI AEs, and gastric bleeding has been observed. Glucocorticoids are not recommended for upper GI bleeding and should be carefully used for cases without bleeding. Diarrhea and colitis are the most common lower GI AEs characterized by inflammation of the mucosa, and high-dose glucocorticoids with other immunomodulators are recommended as salvage treatments. Constipation and paralytic bowel obstruction caused by dysfunction of the GI tract are less frequent and respond well to medications promoting bowel movements. Severe GI AEs should be managed by a multidisciplinary team based on a comprehensive assessment of disease severity. Further clinical trials are warranted to investigate the optimal management of GI AEs.