Nickan Research Institute Journal of Parathyroid Disease 2345-6558 13 1 2025 01 01 Association between glucagon-like peptide-1 receptor agonists and thyroid carcinoma; a systematic review and meta-analysis of observational studies e13293 e13293 10.34172/jpd.2025.13293 EN Mojtaba Lotfi https://orcid.org/0000-0003-1762-391X Mahboobeh Akhondi https://orcid.org/0000-0002-8391-6553 Mehrangiz Ghafari https://orcid.org/0000-0003-2942-4651 Mahmoud Dehghani-ghorbi https://orcid.org/0000-0001-7272-3804 Mehrnaz Nazari Rad https://orcid.org/0009-0003-8341-8153 Maedeh Seifollahi Marbini https://orcid.org/0009-0003-4884-7227 Mahsa Ebrahimi https://orcid.org/0000-0003-2264-0204 Seyed Amir Sheikholeslami https://orcid.org/0000-0002-0069-9785 Sajad Ataei Azimi https://orcid.org/0000-0003-4542-9647 Journal Article 10.34172/jpd.2025.13293 2025 03 14 2025 05 27 Introduction: Glucagon-like peptide-1 receptor agonists (GLP1-RAs) are drugs administered to treat type 2 diabetes mellitus; however, their relationship with thyroid cancer is still unclear. Hence, the present study aimed to examine the association between the use of GLP1-RA and thyroid carcinoma. Materials and Methods: Databases searched—including Web of Science, Cochrane, Scopus, ProQuest, PubMed, Embase, and Google Scholar—were searched without a time limit until May 1, 2025. Data were entered into SPSS 19 and analyzed using STATA 14. Tests with P values less than 0.05 were considered statistically significant (P < 0.05). Results: The relationship between GLP1-RA and thyroid carcinoma based on hazard ratio (HR: 1.14, 95% CI: 0.86, 1.51) and incidence rate ratio (IRR: 1.32, 95% CI: 0.79, 2.20) was statistically insignificant. However, according to odds ratio (OR), use of GLP1-RA increased the risk of thyroid cancer (OR: 1.46, 95% CI: 1.23, 1.74). Furthermore, the association between GLP1-RA and medullary thyroid carcinoma was insignificant (HR: 1.51, 95% CI: 0.90, 2.54). The relationship between GLP1-RA and thyroid carcinoma among women (HR: 1.01, 95% CI: 0.69, 1.47), men (HR: 0.72, 95% CI: 0.33, 1.57), individuals aged 50 to 59 (HR: 1.30, 95% CI: 0.96, 1.75), 60 to 69 (HR: 0.95, 95% CI: 0.65, 1.38), in China (HR: 1.26, 95% CI: 0.91, 1.76), France (HR: 3.43, 95% CI: 1.30, 9.04), and Korea (HR: 1.05, 95% CI: 0.76, 1.46) was statistically insignificant. However, in the USA (HR: 1.44, 95% CI: 1.22, 1.71), GLP1-RA administration increased the risk of thyroid neoplasm. Conclusion: Generally, the relationship between the GLP1-RA use in patients with type 2 diabetes mellitus and the risk of thyroid carcinoma was insignificant. Registration: This study has been compiled based on the PRISMA checklist, and its protocol was registered on the PROSPERO (ID: CRD420251051827) and Research Registry (reviewregistry1993) websites.