More thyroid cancers were detected soon after starting a GLP-1 receptor agonist than other diabetes drugs, a secondary analysis of a pilot simulation targeted for a comparative effectiveness study has found.
Among more than 350,000 adults with type 2 diabetes, the risk of thyroid cancer was significantly higher during the first year after starting a GLP-1 agonist compared with SGLT2 inhibitors, DPP-4 inhibitors, or sulfonylureas (HR 1.85, 95% CI 1.11). -3.08). Rosalina McCoy, MD, MSc, of the University of Maryland School of Medicine in Baltimore, and colleagues.
But when the analysis was expanded beyond the first year—now considering any time period since the start of treatment—GLP-1 agonist use was not significantly associated with thyroid cancer compared with the other three diabetes drug classes (HR 1.24, 95% CI). CI 0.88-1.76), they wrote in JAMA Otolaryngology-Head and Neck Surgery.
Overall, thyroid cancer was diagnosed in 0.17% of the GLP-1 agonist group, 0.17% of the SGLT2 inhibitor group, 0.20% of the sulfonylurea group, and 0.23% of the DPP-4 inhibitor group.
The risk of thyroid cancer was increased for GLP-1 agonist users in the overall treated analysis that controlled for patients when treatment was discontinued or another drug was added (HR 2.07, 95% CI 1.10-3.95).
“We found it [GLP-1 drug use] “It increased the likelihood of being diagnosed with thyroid cancer, but this appears to be not due to an increased likelihood of getting the cancer, but rather an increased likelihood of looking for it,” McCoy said. MedPage Today.
“Find out if GLP-1 RAs [receptor agonists] She added that the cause of thyroid cancer is very important, noting that more and more Americans are turning to this category of diabetes and obesity medications, which It may have additional benefits Beyond these indicators.
“Clinical trials cannot answer this question because they cannot enroll enough patients or follow them long enough to see rare or late effects of the drug,” McCoy said. Observational studies have yielded mixed data, in part because studies examined different populations and used different designs, including variation in when some studies start looking for thyroid cancer—some immediately after patients begin treatment with a GLP receptor agonist— 1 Some of them wait 6 years or more. Months, McCoy said.
Concerns were first raised after rodent models showed an increased risk of thyroid C cell tumors, including medullary thyroid carcinoma, in a dose- and duration-dependent manner. This prompted all labels of GLP-1 agents to include an embedded warning against their use in patients with a personal or family history of this type of cancer.
But fear of this warning may also have prompted doctors to start looking for thyroid cancer in these patients, “despite the fact that this fear has no evidence basis,” McCoy said.
“Patients either notice something in the neck, or we start doing neck scans after patients start treatment with GLP-1 RA — which I don’t think we need to do — but we end up doing an ultrasound and finding that there are risks Low.” She said: Thyroid cancer.
“This tells us that the increase in risk of thyroid cancer diagnosis that we were worried about is real. And we’re seeing it in the data,” McCoy noted.
“But this is not due to the fact that these patients are developing thyroid cancer – it is too early for that to happen, especially since the cancers that are being diagnosed are not the ones that patients die from, which means they are low-risk and presumably slow.” “They grow — but because once they are treated with GLP-1 RA, we start looking for thyroid cancer, and when we look for it we find it,” she added.
The study included 40,956 people with type 2 diabetes who had recently started a GLP-1 agonist, 74,313 on a DPP-4 inhibitor, 52,049 on an SGLT2 inhibitor, and 187,960 on a sulfonylurea. The average age of the participants was 65.3%, of whom 49.3% were female. Median follow-up ranged from 660 days for GLP-1 agonist users to 1245 days for the DPP-4 inhibitor group. New diagnoses of thyroid cancer were identified by ICD-9/10 codes.
McCoy and colleagues noted that initiators of GLP-1 agonists had a significantly higher likelihood of undergoing thyroid ultrasound at 6 and 12 months, suggesting that detection bias was behind the increased cancer diagnosis rate observed in the first year of treatment.
The researchers noted that while the metabolic advantages of GLP-1 agonists may outweigh the potential risk of developing thyroid cancer in some patients, this is not the case for patients at high risk of developing medullary thyroid cancer.
One limitation was the study’s inability to distinguish between cases of medullary thyroid cancer and other subtypes of thyroid cancer. Participants were also limited to those using GLP-1 agonists for diabetes, but not obesity or cardiovascular risk reduction.
Disclosures
The study was funded by the Patient-Centered Outcomes Research Institute (PCORI).
McCoy reports grants from the US National Institute of Diabetes and Digestive and Kidney Diseases, the National Institute on Aging, and the American Diabetes Association, and personal fees from the American Diabetes Association, Yale New Haven Health System, and EmmiEducate outside the submitted work.
Co-authors report relationships with Dexcom, Abbott, Novo Nordisk, Eli Lilly, GlyCare, and Dexcom.
Primary source
JAMA Otolaryngology-Head and Neck Surgery
Source reference: Brito JP, et al. “GLP-1RA Use and Thyroid Cancer Risk” JAMA Otolaryngol Head Neck Surg 2025; doi: 10.1001/jamaoto.2024.4852.
