Diabetes Management and Cancer

Diabetes occurs when the body does not produce enough insulin or respond well to insulin. This makes it harder for the body to process sugar in the blood, causing serious health problems. Cancer patients with diabetes may need specialized care.

There are three main types of diabetes found in cancer patients.

Secondary diabetes is diabetes that develops because of an underlying condition or medication. It is the most common type of diabetes in cancer patients. It can be caused by certain cancer treatments. These include chemotherapy, immunotherapy, steroids, surgery and targeted therapy. Patients who get nutrition through a feeding tube or an IV are also at risk. Inflammation and infection can also cause secondary diabetes.

In most cases, secondary diabetes goes away when treatment is done. For some patients, especially those with risk factors for diabetes, the condition may remain after treatment or progress to Type 2 diabetes.

Secondary diabetes in cancer patients is treated with dietary changes, oral medications and/or insulin injections.

The other two types of diabetes are usually diagnosed before the patient’s cancer, though sometimes cancer treatments can contribute to their development.

Type 2 diabetes impacts about 20% of cancer patients. It occurs when the pancreas produces insulin, but cells do not respond well to it. This is known as insulin resistance. Obesity is a major cause of insulin resistance. Type 2 diabetes can be managed with healthy eating, regular exercise (five to seven days a week), oral medications and/or insulin injections.

Type 1 diabetes is a rare condition. It occurs when the pancreas produces no insulin or too little insulin to process blood sugar. Type 1 diabetes is typically diagnosed in patients under 30. Some forms develop in patients in their 50s and 60s. In cancer patients, certain treatments, such as a complete pancreatectomy (removal of the pancreas) or immunotherapy-induced diabetes, can result in Type 1 diabetes.

Diabetes and Cancer

Patients with diabetes are at a higher risk of developing several cancers. These include pancreatic cancer, endometrial cancer and liver cancer.

Some research shows that cancer patients with Type 1 or Type 2 diabetes and high blood sugar (or hyperglycemia) have worse outcomes compared to cancer patients without diabetes. The link between cancer and diabetes is still being explored.

Most cancer patients with Type 1 or Type 2 diabetes need to adjust their medication during treatment. These changes should account for differences in appetite and activity levels, as well as the impact of cancer treatments.

Even in patients who do not have diabetes, hyperglycemia can contribute to infections and make it harder for the body to heal wounds. In some cases, it can delay surgery and disqualify patients from clinical trials.

Some treatments, including steroids and certain chemotherapy drugs, can cause hyperglycemia, so it is important for patients to monitor and control blood sugar during cancer treatment. Patients with hyperglycemia may need medications or insulin therapy.