Overscreening of patients on glucagon-like peptide-1 receptor agonists: A second "epidemic" of thyroid cancer overdiagnosis?

Abstract

Guidelines do not recommend routine screening for thyroid nodules when starting a glucagon-like peptide-1 receptor agonist. Patients, however, increasingly present with incidental nodules from imaging ordered at glucagon-like peptide-1 receptor agonist initiation. This retrospective case-control study examined patients in a single academic health system from 1 January 2019 to 31 December, 2024 who underwent thyroid ultrasound, fine-needle aspiration biopsy, molecular testing, and/or surgery with glucagon-like peptide-1 receptor agonist initiation compared with patients not prescribed a glucagon-like peptide-1 receptor agonist. Patient, prescription, and intervention data were collected. Chart review was also performed for a subset of patients. From 2019 to 2024, 2,523 patients prescribed a glucagon-like peptide-1 receptor agonist underwent thyroid ultrasound; from 2020 to 2023, there was a higher growth rate of ultrasound scans ordered for them. A random sample of 415 patients prescribed a glucagon-like peptide-1 receptor agonist showed that most ultrasounds were ordered for "thyroid nodules" by the endocrinologist who prescribed glucagon-like peptide-1 receptor agonist. In this subset, 757 nodules were detected on ultrasound; 10.6% (80/757) had fine-needle aspiration biopsy. Cytology showed 3.8% were Bethesda I (3/80), 72.5% Bethesda II (58/80), 15% Bethesda III (12/80), 0% Bethesda IV (0/80), 2.5% Bethesda V (2/80), and 6.6% Bethesda VI (5/80). Of 15 indeterminate nodules, 11 had molecular testing: 5 were positive or suspicious, including fusions, alterations, RAS and BRAF mutations. Sixteen patients had thyroid surgery after glucagon-like peptide-1 receptor agonist initiation (8 total thyroidectomies, 8 hemithyroidectomies, 1 completion). Final pathology demonstrated 6 benign, 10 malignant, 1 NIFTP. The rate of malignancy in the subset was 2.4% (10/415). The malignancy rate in patients prescribed a glucagon-like peptide-1 receptor agonist remains low, but ultrasound screening rates increased for a period. Strong clinical suspicion should govern screening.