Endocrinopathies associated with immune checkpoint inhibitor use

Objective To provide a clinical approach towards immune checkpoint inhibitor (ICI)-associated endocrinopathies, their link with cancer outcomes, factors which differentiate them from other immune related adverse events (irAEs), and health systems innovation to improve care for these patients. Methods A literature search for articles pertaining to ICIs and endocrinopathies was performed and supplemented by expert opinions of the authors. Results While irAEs can affect almost any organ, they frequently target the endocrine glands, most commonly thyroid. Different classes of ICIs have varying frequencies of endocrinopathies related to hypophysitis, thyroiditis, diabetes mellitus, and rarely hypoadrenalism and hypoparathyroidism. ICI-associated endocrinopathies share some features with classic endocrine autoimmunity but appear to be a distinct entity. They can be challenging to diagnose and manage due to non-specific clinical features, use of exogenous glucocorticoids, and at times rapid and severe hormone deficiency. The role of anti-inflammatory high-dose glucocorticoids is minimal, and the ICI does not usually require permanent discontinuation. ICI-associated endocrinopathies usually cause permanent hormone deficiency necessitating long-term management and patient engagement. ICI-thyroiditis has been associated with improved survival, while other endocrinopathies have not shown a significant association with outcomes in cancer patients receiving ICIs. Onco-endocrinology teams can improve the care of patients with ICI-associated endocrinopathies. Conclusion This narrative review provides guidance to clinicians prescribing ICIs and those managing ICI-associated endocrinopathies, and complements the frameworks provided by major scientific societies in this field.