Medullary Thyroid: RET Focus
- CURE on March 7 and CancerNetwork on March 2 put the focus on medullary thyroid cancer as a C-cell disease where diagnosis and treatment hinge on RET genetics, calcitonin and surgery. - The CURE review said medullary thyroid cancer makes up about 1% to 2% of U.S. thyroid cancers, with roughly 25% hereditary through RET mutations and about 75% sporadic adult-onset cases. - The same March reporting said GLP-1 warnings are specific to medullary thyroid carcinoma and MEN2, not the common thyroid cancers that make up most cases. (curetoday.com) (cancernetwork.com)
Medullary thyroid cancer starts in the thyroid’s calcitonin-making C cells, not in the hormone-making follicular cells that drive most thyroid cancers. (curetoday.com) That cell of origin changes the workup. CURE reported on March 7 that clinicians use fine-needle aspiration, blood markers including calcitonin and carcinoembryonic antigen, ultrasound, and added imaging when those markers suggest spread. (curetoday.com) The genetic piece is central because medullary thyroid cancer can be inherited. CURE said about 25% of cases are hereditary and linked to RET mutations in multiple endocrine neoplasia type 2, while about 75% are sporadic. (curetoday.com) That is why RET testing is not an add-on after the microscope. The review described universal RET testing and family cascade screening as part of routine care, alongside checks for other tumors tied to MEN2. (curetoday.com) Treatment follows the biology. Because medullary thyroid cancer does not take up iodine, radioactive iodine used in papillary or follicular thyroid cancer does not work here, and surgery is the main curative treatment. (curetoday.com) CURE said primary treatment is total thyroidectomy with routine central neck dissection and selective lateral neck dissection when lymph nodes are involved. For unresectable or metastatic disease, the review listed vandetanib, cabozantinib, selpercatinib, and pralsetinib. (curetoday.com) The parallel March 2 CancerNetwork white paper addressed a different anxiety around thyroid cancer and weight-loss drugs. It said there was no convincing evidence that glucagon-like peptide-1 receptor agonists cause papillary, follicular, or oncocytic thyroid cancers. (cancernetwork.com) CancerNetwork said the Food and Drug Administration boxed warning comes from rodent studies showing C-cell tumors, not from proof of the same effect in humans. The article also said human studies have not shown a clinically meaningful rise in calcitonin with these drugs. (cancernetwork.com) (accessdata.fda.gov) The boxed warning still matters for a specific group. The current Wegovy label says semaglutide is contraindicated in patients with a personal or family history of medullary thyroid carcinoma or with multiple endocrine neoplasia syndrome type 2. (accessdata.fda.gov) Put together, the March coverage draws a sharper line: medullary thyroid cancer is the thyroid cancer where RET status, calcitonin, and C-cell biology drive decisions, and the GLP-1 warning is aimed at that rare disease rather than the common thyroid cancers. (curetoday.com) (cancernetwork.com)
