Cytotoxic T-lymphocyte associated
antigen 4(CTLA-4), programmed death 1(PD-1), and
programmed death-ligand 1 (PD-L1)are referred to as immune-checkpoints. CTLA-4 is located on the surface of activated T-cells, therefore inhibiting binding of CD28 to B7 molecule on antigen presenting cells. The CTLA-4 pathway predominantly acts in lymph nodes. PD-1 is majorly expressed on T-cells. The PD-1 pathway is involved with tumor microenvironment.
Immune-checkpoint inhibitors (ICIs)are
monoclonal antibodies to these molecules and are promising novel agents for malignant
tumor treatment. ICIs promote T-cell-mediated cytotoxicity directed at
cancer cell
antigens. Approximately 20-30% of patients with advanced
cancer were found to be responders of ICIs. However, various adverse events have been reported as immune-related adverse events(irAEs). IrAEs include dermatological, gastrointestinal, hepatic, neurological, and endocrine disorders. In the endocrine system, irAEs in the pituitary glands, thyroid glands, pancreas, and adrenal glands have been reported. Since rapidly progressive fatal endocrine systems failure may provoke during ICI
therapy, precise diagnosis and prompt treatment as well as close follow-up is critical. We propose routine monitoring of endocrine functions and related symptoms(ie. worsened
fatigue,
hyperglycemia,
hypoglycemia,
hypotension, and
hyponatremia), as well as other laboratory tests during ICI
therapy. We herein discuss possible mechanisms of endocrine irAEs with ICIs, and highlight diagnostic approaches, treatments, and future prospects of endocrine irAEs during ICI
therapy.