Does GLP-1 drug affect thyroid cancer risk?

A study published in the journal The BMJ found no significant increase in thyroid cancer risk for people with type 2 diabetes on GLP-1 agonists compared with people treated with DPP4 inhibitors.

Glucagon-like peptide-1 receptor (GLP-1) agonists are an effective treatment for controlling blood glucose levels in people with type 2 diabetes, particularly those who do not respond, or stop responding to, first-line treatments, such as metformin. One concern about the medicationsis that some studies suggest they may increase the risk of thyroid cancer.However, these studies point out that the health benefits of the drugs are likely to outweigh this increased risk.

The study used data on more than 145,000 people treated with GLP-1 agonists, and almost 292,000 people treated with DPP4 inhibitors.The researchers followed up participants after a mean of 3.9 years for the GLP-1 group and 5.4 years for the DPP4 group. They identified cases of thyroid cancer from nationwide cancer registers. 

The results revealed that in the GLP-1 group, 76 of 145, 410 people developed thyroid cancer, and in the DPP4 group, 184 of 291, 667 developed the disease. The researchers concluded that the relative risk was increased by no more than 31% for those on GLP-1 agonists.

“The meaning of relative risk is the risk compared to someone not taking the medication — 31% is very low and indicates that the risk of developing thyroid cancer due to this medication is relatively low,” said Mir Ali, MD, medical director of MemorialCare Surgical Weight Loss Center.

Reference: Björn Pasternak, Viktor Wintzell, Anders Hviid, Björn Eliasson, et al; Glucagon-like peptide 1 receptor agonist use and risk of thyroid cancer: Scandinavian cohort study; BMJ 2024; 385 doi: https://doi.org/10.1136/bmj-2023-078225