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10 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
Medullary thyroid cancer comes from the calcitonin-making C cells, not the thyroid hormone cells, so radioactive iodine does not work. Surgery is the only cure, a quarter of cases run in families through the RET gene, and the RET-selective drug selpercatinib has transformed treatment of advanced disease.
Medullary thyroid cancer arises from the parafollicular C cells and secretes calcitonin, which serves as its tumour marker. Germline RET mutations cause the hereditary forms (MEN2A, MEN2B and familial medullary thyroid cancer), and children who inherit them have the thyroid removed before cancer develops, timed by the mutation's risk level; most sporadic tumours carry a somatic RET M918T mutation, and a minority RAS mutations. Total thyroidectomy with central neck dissection is the only curative treatment, and calcitonin doubling time guides follow-up. For progressive advanced disease, vandetanib (2011) and cabozantinib (2012) were the first approved kinase inhibitors; selpercatinib, a RET-selective inhibitor, beat them in the LIBRETTO-531 trial and is now the standard for RET-mutant disease, with pralsetinib as an alternative. Phaeochromocytoma must be excluded before any thyroid surgery in MEN2.
| Setting | Approach | Guideline |
|---|---|---|
| Hereditary RET carriers | Prophylactic total thyroidectomy in childhood, timed by the RET codon risk category (before age one in MEN2B). | not mapped |
| Localised disease | Total thyroidectomy with central compartment dissection, lateral dissection when nodes are involved; no radioactive iodine; levothyroxine replacement only. | not mapped |
| Advanced RET-mutant disease | Selpercatinib first line (LIBRETTO-531 beat cabozantinib and vandetanib); pralsetinib as an alternative. | not mapped |
| Advanced RET-negative disease | Cabozantinib or vandetanib; external radiotherapy for local control; somatostatin analogues for diarrhoea from calcitonin. | not mapped |