GLP-1 Receptor Agonists Don’t Raise Thyroid Cancer Risk

TOPLINE:

No significant association was found between the use of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) and thyroid cancer over nearly 4 years.

METHODOLOGY:

• A cohort study using data from nationwide registers in Denmark, Norway, and Sweden between 2007 and 2021 included 145,410 patients who initiated GLP-1 RAs and 291,667 propensity score-matched patients initiating dipeptidyl peptidase 4 (DPP4) inhibitors as active comparators.
• Additional analysis included 111,744 who initiated GLP-1 RAs and 148,179 patients initiating sodium-glucose cotransporter 2 (SGLT2) inhibitors.
• Overall, mean follow-up time was 3.9 years, with 25% followed for more than 6 years.

TAKEAWAY:

• The most common individual GLP-1 RAs were liraglutide (57.3%) and semaglutide (32.9%).
• During follow-up, there were 76 incident thyroid cancer cases among GLP-1 RA users and 184 cases in DPP4 inhibitor users, giving incidence rates per 10,000 of 1.33 and 1.46, respectively, a nonsignificant difference (hazard ratio [HR], 0.93; 95% CI, 0.66-1.31).
• Papillary thyroid cancer was the most common thyroid cancer subtype, followed by follicular and medullary, with no significant increases in risk with GLP-1 RAs by cancer type, although the numbers were small.
• In the SGLT2 inhibitor comparison, there was also no significantly increased thyroid cancer risk for GLP-1 RAs (HR, 1.16; 95% CI, 0.65-2.05).

IN PRACTICE:

“Given the upper limit of the confidence interval, the findings are incompatible with more than a 31% increased relative risk of thyroid cancer. In absolute terms, this translates to no more than 0.36 excess cases per 10 000 person-years, a figure that should be interpreted against the background incidence of 1.46 per 10,000 person-years among the comparator group in the study populations.”

SOURCE:

This study was conducted by Björn Pasternak, MD, PhD, of the Karolinska Institutet, Stockholm, and colleagues. It was published online on April 10, 2024, in The BMJ.

LIMITATIONS:

Relatively short follow-up for cancer risk. Risk by individual GLP-1 RA not analyzed. Small event numbers. Observational, with potential for residual confounding and time-release bias.

DISCLOSURES:

The study was supported by grants from the Swedish Cancer Society and the Swedish Research Council. Dr. Pasternak was supported by a consolidator investigator grant from Karolinska Institutet. Some of the coauthors had industry disclosures.

A version of this article appeared on Medscape.com.