Diabetes is a risk factor for several types of cancer and some previous research suggests cancer increases the risk of developing new diabetes.

Now, developing cancer was associated with increased risk for later diabetes, based on data from a nationally representative sample of the Korean general population.

This observational study is published in JAMA Oncology.

Researchers were not intervening for purposes of the study and cannot control for all the natural differences that could explain the study results.

524,089 men and women ages 20 to 70 were surveyed as a nationally representative sample of the Korean general population who had no history of cancer and were followed for up to 10 years (2003-2013), assessing the incidence of new diagnoses of cancer and type 2 diabetes in insurance claim codes.

Cancer was associated with an increased risk of diabetes, even after taking into account precancer risk factors, and that increased risk was highest in the first two years after cancer diagnosis:

• Pancreatic: HR 5.15 (95% CI 3.32-7.99)
• Kidney: HR 2.06 (95%CI 1.34-3.16)
• Liver: HR 1.95 (95%CI 1.50-2.54)
• Gallbladder: HR 1.79 (95%CI 1.08-2.98)
• Lung: HR 1.74 (95% CI 1.34-2.24)
• Blood: HR 1.61 (95%CI 1.07-2.43)
• Breast: HR 1.60 (95%CI 1.27-2.01)
• Stomach: HR 1.35 (95%CI 1.16-1.58)
• Thyroid cancer: HR 1.33 (95% CI 1.12-1.59)

"The increased risk of diabetes after cancer may be related to cancer-management interventions," the authors explained.

"Corticosteroid use is associated with hyperglycemia and with diabetes development, a process mediated primarily by reduced insulin sensitivity," they wrote, highlighting that corticosteroid use is commonly used throughout cancer treatment including in "the prevention of chemotherapy-induced emesis and hypersensitivity, the management of brain metastasis and metastatic spinal cord compression, the control of hematologic cancers, and the reduction of cancer-related fatigue, and improvement of quality of life."

The authors conclude "Physicians should remember that patients with cancer develop other clinical problems, such as diabetes, with higher frequency than individuals without cancer, and should consider routine diabetes screening in these patients."

Source: JAMA Oncology