Cancers That Cause Hyperglycemia

Pancreatic Cancers

Pancreatic adenocarcinoma can cause hyperglycemia by destroying insulin-producing beta cells in the pancreas, leading to impaired insulin secretion and subsequent hyperglycemia 1
Sudden onset of type 2 diabetes in patients over 50 years of age may be an early warning sign of pancreatic cancer and should prompt consideration of this diagnosis, especially when accompanied by weight loss and abdominal symptoms 2
Pancreatic cancer can cause diabetes even when only a small portion of the pancreas is involved, suggesting mechanisms beyond simple reduction in beta-cell mass 1

Glucagonomas are pancreatic neuroendocrine tumors that secrete excessive glucagon, directly causing hyperglycemia by antagonizing insulin action 3
The classic presentation includes the "glucagonoma syndrome" with necrolytic migratory erythema, diabetes mellitus, weight loss, stomatitis, and diarrhea 3
Diagnosis involves measuring plasma glucagon levels and performing multiphasic CT or MRI in patients with recent-onset diabetes, cachexia, and/or characteristic skin rash 4, 3
Insulinomas, while typically causing hypoglycemia, can paradoxically cause hyperglycemia in certain contexts, particularly during treatment with somatostatin analogs like octreotide 5
Octreotide should be used with caution in patients with insulinoma as it can suppress counterregulatory hormones (growth hormone, glucagon, catecholamines), potentially worsening glycemic control 5

Several hormone-secreting tumors can cause hyperglycemia through insulin antagonism, including acromegaly (growth hormone-secreting pituitary tumors) 4, Cushing's syndrome (cortisol-producing adrenal tumors or ACTH-producing tumors) 6, glucagonomas 5, and pheochromocytomas (catecholamine-secreting tumors) 5
Somatostatinomas and aldosteronoma-induced hypokalemia can cause diabetes partly by inhibiting insulin secretion 1

Corticosteroids used in cancer treatment commonly cause hyperglycemia through multiple mechanisms, including deterioration of insulin secretion by pancreatic beta cells 1, increased insulin resistance in peripheral tissues 7, enhanced hepatic gluconeogenesis 7, and increased renal glucose reabsorption 7
Immune checkpoint inhibitors can cause checkpoint inhibitor-associated diabetes mellitus (CIADM), which presents similarly to type 1 diabetes with autoimmune destruction of beta cells 8, 6
Cancer patients with insulin resistance may benefit from increasing the ratio of fat to carbohydrates in their diet to reduce glycemic load 9

Weight-losing cancer patients often develop insulin resistance, which impairs glucose uptake and oxidation in muscle cells 9
Monitoring recommendations for patients on immune checkpoint inhibitors should be tailored to their risk of developing significant hyperglycemia 8
Patients with pre-existing diabetes and cancer should have careful glucose monitoring, particularly when starting treatments like corticosteroids 8, 7

Corticosteroids are the leading cause of hyperglycemia in cancer patients, accounting for 68-76% of all new-onset hyperglycemia cases in those receiving immune checkpoint inhibitors, according to the American Society of Clinical Oncology 10, 11
Up to 35% of ICI-treated patients receive corticosteroids for immune-related adverse events, making this a highly prevalent issue, as reported by the National Comprehensive Cancer Network 12
Checkpoint inhibitor-associated autoimmune diabetes mellitus (CIADM) occurs in 0.4%-1.9% of patients treated with ICIs, with the American Diabetes Association noting that this condition can progress to life-threatening diabetic ketoacidosis 10, 12
Combination therapy with 2 or more ICIs increases the risk of hyperglycemia substantially (3.37% all-grade, 0.47% serious hyperglycemia), as stated by the European Society for Medical Oncology 11

Cancer patients have inherently increased risk of developing hyperglycemia and new-onset diabetes irrespective of treatment factors, according to the American Cancer Society 10, 13

In patients with known diabetes, 42-72% experience hyperglycemia when treated with ICIs, with the Endocrine Society recommending close monitoring of blood glucose levels in these patients 10, 12
Overall incidence of hyperglycemia ranges from 13-27% of all ICI-treated patients, as reported by the Journal for ImmunoTherapy of Cancer 10, 14

Several studies demonstrate an association between hyperglycemia and lower overall survival and increased risk of cancer recurrence, with the American Society of Clinical Oncology emphasizing the importance of managing hyperglycemia in cancer patients 10, 13