Acute Hyperglycemia Associated with Anti-Cancer Medication

Hyperglycemia during chemotherapy occurs in approximately 10% to 30% of patients. Glucocorticoids and L-asparaginase are well known to cause acute hyperglycemia during chemotherapy. Long-term hyperglycemia is also frequently observed, especially in patients with hematologic malignancies treated with L-asparaginase-based regimens and total body irradiation. Glucocorticoid-induced hyperglycemia often develops because of increased insulin resistance, diminished insulin secretion, and exaggerated hepatic glucose output. Screening strategies for this condition include random glucose testing, hemoglobin A1c testing, oral glucose loading, and fasting plasma glucose screens. The management of hyperglycemia starts with insulin or sulfonylurea, depending on the type, dose, and delivery of the glucocorticoid formulation. Mammalian target of rapamycin (mTOR) inhibitors are associated with a high incidence of hyperglycemia, ranging from 13% to 50%. Immunotherapy, such as anti-programmed death 1 (PD-1) antibody treatment, induces hyperglycemia with a prevalence of 0.1%. The proposed mechanism of immunotherapy-induced hyperglycemia is an autoimmune process (insulitis). Withdrawal of the PD-1 inhibitor is the primary treatment for severe hyperglycemia. The efficacy of glucocorticoid therapy is not fully established and the decision to resume PD-1 inhibitor therapy depends on the severity of the hyperglycemia. Diabetic patients should achieve optimized glycemic control before initiating treatment, and glucose levels should be monitored periodically in patients initiating mTOR inhibitor or PD-1 inhibitor therapy. With regard to hyperglycemia caused by anti-cancer therapy, frequent monitoring and proper management are important for promoting the efficacy of anti-cancer therapy and improving patients' quality of life.