Do GLP-1 Receptor Agonists Increase Thyroid Cancer Risk? Reassuring Evidence from over Two Million Patients

Sunday, October 18, 2026

1:06 PM - 1:12 PM PT

Location: Theatre 411

Presenting Author(s)

Nicholas M. Del Mundo, MD

Dr.
Kaiser Permanente Med Group - Northern California
Oakland, CA, United States

Co-Author(s)

KL

Kathy C. Le, MPH

Data Analyst
Kaiser Permanente Northern California Division of Research
San Jose, CA, United States
MW

Miranda Weintraub, PhD

Dr.
Kaiser Permanente Northern California, United States
JW

Julia C. Wei, MPH

Data Analyst
Kaiser Permanente Northern California Division of Research
Sacramento, CA, United States
JF

Justin Fong, MD

Resident Physician
Kaiser Permanente Northern California, United States
KW

Kevin H. Wang, MD

Head and Neck Surgeon
Kaiser Permanente
Orinda, CA, United States

Senior Author(s)

JL

Jonathan Liang, MD

Associate Professor
Kaiser Permanente
Oakland, California, United States

Disclosure(s):

Nicholas M. Del Mundo, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Kathy C. Le, MPH:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Julia C. Wei, MPH:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Kevin H. Wang, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Introduction: Use of glucagon-like peptide-1 receptor agonists (GLP1RA) has rapidly expanded due to benefits in glycemic control, weight loss, and cardiovascular risk reduction. Animal studies have prompted boxed-warnings describing increased risk for thyroid cancer, but the relationship between GLP1RA exposure and the development of thyroid cancer in humans remains incompletely understood. We aim to investigate if the use of GLP1RA is associated with an increased risk of thyroid cancer using data from a large, integrated health system.

Methods: A retrospective cohort study of patients between 1/1/2018 and 12/31/2022 at a large integrated health care system was performed. Inclusion criteria included age 18yrs and older and at least 1 year of continuous membership. Exclusion criteria included previous history of GLP1RA use, thyroid cancer, or thyroid surgery. Patients were categorized as GLP1RA users and non-users. GLP1RA medications included dulaglutide, exenatide, lixisenatide, liraglutide, semaglutide, and tirzepatide. Thyroid cancers were identified through the cancer registry. Descriptive statistics and logistic regression were performed, and an odds ratio (OR) was calculated.

Results: Our study cohort consisted of 2,514,242 patients with mean age of 49.2 years [SD 17.95]; 47.2% men and 52.7% women. Among these, 14,057 were GLP1RA users with mean age of 55.9 [SD 11.95]; 58.2% men and 41.7% women. The most used GLP1RA medications were liraglutide (67.7%) and semaglutide (25.1%). The incidence of thyroid cancer in the GLP1RA users was 10 per 100,000 patients per person-year and the incidence amongst non-GLP1RA users was 13.2 per 100,000 patients per person-year. Seven GLP1RA users developed thyroid cancer (6 papillary, 1 anaplastic). There was no significant association of incident thyroid cancer in GLP1RA users compared to non-GLP1RA users (OR 0.75; 95% CI 0.36-1.58).

Conclusions: This is the largest study in the US evaluating thyroid cancer risk in the GLP1RA user population. There were few incident thyroid cancer cases and no overall increased risk of incident thyroid cancer compared with non-users.