New study links diabetes drugs to reduced cancer risk

A recent study published in JAMA Network Open has revealed that certain diabetes treatments might lower the risk of obesity-related cancers.

Researchers compared the effects of three diabetes medications: glucagon-like peptide receptor agonists (GLP-1RAs), insulin, and metformin, on cancer risk among people living with type 2 diabetes.

The study found that participants using GLP-1RAs had a significantly lower risk of developing 10 out of 13 obesity-related cancers compared to those using insulin. These cancers include gallbladder, pancreatic, ovarian, colorectal, and esophageal cancers. However, no significant risk reduction was observed for breast or thyroid cancer.

Obesity is a known risk factor for several types of cancer, including colorectal, breast, endometrial, kidney, and pancreatic cancers. Dr Wael Harb, a board-certified hematologist and medical oncologist, explained that obesity can promote cancer development through mechanisms such as chronic inflammation, insulin resistance, and altered hormone levels.

The study analysed data from over 1.6 million people with type 2 diabetes, none of whom had a history of the 13 obesity-related cancers. Researchers tracked these individuals over 15 years, examining the incidence of these cancers among those taking GLP-1RAs, insulin, or metformin.

Compared to insulin users, those on GLP-1RAs had a notably lower risk for several cancers. When comparing GLP-1RAs with metformin, the reduction in risk for colorectal and gallbladder cancers was observed but not statistically significant. Interestingly, GLP-1RA users showed an increased risk for kidney cancer compared to metformin users.

Dr Harb emphasised the potential clinical implications, suggesting that GLP-1RAs might be prioritised for managing type 2 diabetes in patients at high risk for obesity-related cancers. This dual benefit could enhance both glycemic control and cancer prevention.

However, the study has limitations, including the potential for diagnosis errors, bias, and confounding factors due to its reliance on electronic health records. Future research should further investigate these findings and explore the mechanisms behind GLP-1RAs' protective effects against cancer.

Dr. Anton Bilchik, a surgical oncologist, cautioned that while the study shows a reduction in several cancers, it remains unclear if this is directly due to GLP-1 drugs or weight loss resulting from their use. Further research is needed to clarify these effects and confirm the results.