Endocrinopathies as a price of cancer treatment

Abstract

Many drugs are used in treatment of cancer. Including chemotherapy, hormonal therapy and immunotherapy. The investment of immunotherapy has improve the procedure for treating cancer by utilizing the immune system to identify and attack cancer cells through immune checkpoint inhibitors. This is done by two major mechanisms, the first is CTLA-4 inhibitors like ipilimumab, and the second pathways is PD-1/PD- L1 inhibitors like nivolumab. However many adverse effects have aroused as a consequence of immunotherapy usage. Including non-endocrinal adverse effects like colitis and dermatitis, and endocrinal side effects predominantly involving pituitary and thyroid gland plus the endocrine pancreas. Pituitary gland involvement is potentially life threatening and is mainly due to CTLA-4 inhibitors, leading to multiple pituitary hormone deficiencies. It mainly present with headache, and pituitary enlargement is reported in MRI. Which is treated by high dose glucocorticoids to prevent chiasmal compression. Hormone replacement therapy is required according to the deficient hormone. Thyroid gland is one of the most commonly involved glands. Predominately by a combination of both PD-1 and CTLA-4 inhibitors. It mainly present with transient hyperthyroidism followed by hypothyroidism, which is treated by levothyroxine replacement therapy. Immunotherapy will result in both endocrine and exocrine dysfunction. ICIs associated DM is classified into four different types according to the pathology. It includes all of Acute autoimmune insulin-dependent diabetes, type 2 diabetes-like phenotype, autoimmune pancreatitis-induced diabetes, and diabetes after autoimmune lipoatrophy. Patients presented with d ketoacidosis are treated with standard approach while stable patient will be subjected to a regular insulin regimen.