Medullary Thyroid Carcinoma

Introduction to Medullary Thyroid Carcinoma

Medullary thyroid carcinoma (MTC) is associated with multiple endocrine neoplasia syndrome type 2 (MEN2), as noted by the American Gastroenterological Association 1

Multiple endocrine neoplasia syndrome type 2 (MEN2) is associated with an increased risk of MTC, according to the American Gastroenterological Association 1
Familial non-medullary thyroid cancer (FNMTC) has different genetic mechanisms than medullary thyroid cancer and is not associated with the RET gene mutations that cause MEN2 and MTC, as stated by the American College of Medical Genetics and Genomics and the National Cancer Institute 2, 3
Semaglutide is contraindicated in patients with a personal or family history of MTC or MEN2 due to the established risk of thyroid C-cell tumors in rodent studies and potential risk in humans, as recommended by the American College of Cardiology and other medical societies 4, 5

Patients with a personal history of MTC, family history of MTC, or MEN2 syndrome should not be prescribed semaglutide, according to the American College of Cardiology and other medical societies 4, 5
The Kidney International and other medical societies suggest considering cardiovascular and renal benefits of semaglutide when assessing the benefit-risk profile for eligible patients 6
The Gastroenterology society recommends weighing the theoretical thyroid cancer risk against the benefits of semaglutide and implementing appropriate dose titration to minimize adverse effects 1
Patients should be counseled about the potential risk of MTC and symptoms of thyroid tumors (neck mass, dysphagia, hoarseness, persistent cough), as recommended by the American College of Cardiology 4, 5

For patients on levothyroxine after thyroidectomy, the Gastroenterology society recommends monitoring thyroid function more frequently when initiating semaglutide, as cases of suppressed TSH have been reported 1
The Kidney International society suggests considering dose adjustments of thyroid medication if changes in thyroid function are observed 6
Routine thyroid cancer screening is not recommended solely based on GLP-1 RA use, as this could lead to overdiagnosis, according to the American College of Cardiology and other medical societies 4, 5