Increased GLP-1 Thyroid Cancer Risks May Be Product of More Intense Screening, Study Finds

Scientists call for more research into the association between drugs like Ozempic and Mounjaro and thyroid cancer.

A recent study raises questions about whether GLP-1 drugs like Ozempic and Mounjaro actually increase thyroid cancer risks, indicating that previously suggested associations may be the result of more intensive screening, rather than side effects the drugs have on the body.

Researchers from the Mayo Clinic and Yale School of Medicine published a study in JAMA Otolaryngology Head Neck Surgery on January 23, which found that the increase in thyroid cancer diagnosis linked to glucagon-like peptide-1 (GLP-1) receptor agonists disappeared after the first year of treatment, when compared to other diabetes medications.

This class of medications has grown rapidly in the last couple of years, as both diabetes treatments like Ozempic, Mounjaro and Trulicity, and weight loss drugs, like Wegovy and Zepbound have found increased use. However, concerns have emerged about side effects of GLP-1, and whether the manufacturers fully researched all of the potential health risks.

Thousands of former users are now pursuing Ozempic lawsuits, Wegovy lawsuits and Mounjaro lawsuits against the manufacturer, each raising similar allegations that the drug makers failed to adequately disclose gastrointestinal problems linked to the drugs.

In the new study, a team led by Dr. Juan P. Brito, of the Mayo Clinic, looked at data from January 1, 2014 to December 31, 2021 on 351,913 patients who started taking either a GLP-1 drug, a sodium-glucose cotransporter 2 inhibitor (SGLT2i) like Jardiance or Farxiga, dipeptidyl peptidase-4 inhibitor (DPP4i) like Januvia and Onglyza, or a sulfonylurea such as Glucotrol.

“GLP-1RA initiation was not significantly associated with increased overall risk for thyroid cancer compared to the other 3 diabetes drugs,” the researchers noted. “However, the risk for thyroid cancer was significantly higher within the first year after GLP-1RA initiation and was amplified in the overall as-treated analysis that censored patients when therapy was discontinued or another medication was added.”

The research team indicates this could be a sign that GLP-1 users are being screened for thyroid cancer at a higher rate than other diabetes drugs, resulting in a spike in diagnoses in the first year of taking the drug.

“This finding may have been due to enhanced early detection; therefore, further research is necessary to understand the underlying causes of this association,” Brito’s team concluded.

GLP-1 Side Effects Litigation

The study’s findings come as more than 1,300 lawsuits are currently being pursued against the makers of Ozempic, Wegovy, Mounjaro and other similar diabetes and weight loss drugs, each raising similar allegations that a desire for increased profits was placed above consumer safety by failing to research and disclose gastroparesis side effects users may experience.

Given common questions of fact and law raised in complaints filed throughout the federal court system, all GLP-1 lawsuits have been centralized as part of a multidistrict litigation (MDL) in the Eastern District of Pennsylvania, where they are currently being overseen by U.S. District Judge Karen Marston.

Judge Marston has directed the parties to focus in the early stages of the litigation on “cross cutting” issues, which will impact a large number of claims. This includes discovery and pretrial motions regarding general causation evidence about the link between Ozempic and ileus, gastroparesis and other injuries, as well as questions about whether the claims are preempted by federal law and whether plaintiffs will be required to provide specific testing evidence to establish they suffered an injury.

Following the resolution of those issues, Judge Marston is expected to direct the parties to select representative GLP-1 lawsuits for early bellwether test trials, to help gauge how juries will respond to evidence and expert testimony likely to be repeated throughout the litigation.

While the outcomes of such early test trials are not binding on other claims, they could help potentially facilitate a GLP-1 settlement agreement that would avoid the need for each individual case to be set for trial in the future.