Sicca syndrome associated with immune checkpoint inhibitor therapy

Cancer immunotherapy, which seeks to stimulate a patient's own immune system to combat cancer, is quickly becoming a central pillar of cancer therapeutics and has resulted in the development of many novel anticancer therapies. One subtype of cancer immunotherapy, immune checkpoint inhibitors (ICIs), has revolutionized cancer treatment and changed the standard of care for multiple indications. However, the advent of ICIs has produced a wide variety of inflammatory side effects termed immune-related adverse events (IRAEs), including ICI-induced Sicca syndrome. This article outlines the clinical features of ICI-induced Sicca syndrome and assesses its reported incidence in clinical trials, case series, and case reports across numerous cancers and treatment modalities. Presentations of ICI-induced Sicca syndrome in patients with pre-existing Sjӧgren's disease and with extra-glandular manifestations will also be explored. The pathophysiological mechanisms underlying IRAEs, including ICI-induced Sicca syndrome, will be evaluated through an examination of existing literature. Finally, the various treatment and management strategies as well as aims for future work will be discussed and reviewed.