GLP-1 receptor agonists and the risk of thyroid cancer

Objective

To determine whether the use of GLP-1 receptor agonists (RA) is associated with an increased risk of thyroid cancer.

Research Design and Methods

A nested case-control analysis was performed using the French national healthcare insurance system database (SNDS). Individuals with type 2 diabetes treated with second-line antidiabetic drugs between 2006 and 2018 were included in the cohort. All thyroid cancers were identified through hospital discharge diagnoses and medical procedures between 2014 and 2018. Exposure to GLP-1 RA was measured within the 6 years preceding a 6-month lag-time period and considered as current use and cumulative duration of use based on defined daily dose (≤1, 1 to 3, >3 years). Cases were matched with up to 20 controls on age, sex, and length of diabetes, using the risk-set sampling procedure. The risk of thyroid cancer related to the use of GLP-1 RA was estimated using a conditional logistic regression adjusted on goiter, hypothyroidism, hyperthyroidism, other antidiabetic drugs and social deprivation index.

Results

2,562 cases of thyroid cancers were included in the study and matched to 45,184 controls. The use of GLP-1 RA for 1 to 3 years was associated with an increased risk of all thyroid cancer (adjusted hazard ratio: 1.58, 95% confidence interval: 1.27 to 1.95), and medullary thyroid cancer (aHR: 1.78, 95% CI: 1.04 to 3.05). 

Conclusions

The present study found an increased risk of all thyroid cancer and medullary thyroid cancer with the use of GLP-1 RA, in particular after 1 to 3 years of treatment.