Immune-checkpoint inhibitors (ICIs) are novel agents directed to various malignant tumors. During ICI therapy, however, immune related adverse effects (irAEs) including endocrine dysfunctions have been reported. Dysfunctions in the pituitary gland and the thyroid gland by ICI are often observed, and those in the adrenal glands and the pancreas are less frequent. Positive correlation of the prevalence of endocrine irAEs to clinical antitumor effectiveness during ICI therapy has been reported. The mechanisms of endocrine irAEs by ICI, however, remain unclear, and optimal prevention, prediction, and treatment of the irAEs are still uncertain. This review describes possible mechanisms involved in ICI-related immunity, and discusses clinical management of endocrine irAEs during ICI therapy.

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