Approach to the patient with thyroid nodules: considering GLP-1 receptor agonists

Glucagon-like peptide 1 receptor agonists (GLP1RA) have rapidly changed the landscape of diabetes and obesity treatment. Enthusiasm for their use is tempered with concerns regarding their risk for inducing C-cell tumors based on preclinical studies in rodents. A black-box warning from the United States Food and Drug Administration (USFDA) recommends against using GLP1RA in patients with a personal or family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2A or 2B (MEN2), providing clear guidance regarding this cohort of patients. However, emerging data also suggest an increased incidence of differentiated thyroid cancer (DTC) in patients treated with these agents. Other studies, though, have not confirmed an association between GLP1RA and DTC. With conflicting results concerning thyroid cancer risk, there is no clear consensus regarding the optimal approach to screening patients prior to initiating the medications and/or evaluating for thyroid cancer during GLP1RA treatment. Within the context of patient cases, this review will summarize the existing data, describe ongoing controversies, and outline future areas for research regarding thyroid cancer risk with GLP1RA use.