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Short Summary
Main recommendation: For medullary thyroid cancer (MTC), the first surgery is the best chance for cure, typically a total thyroidectomy with removal of involved central and lateral lymph nodes, planned with a neck ultrasound and paired with genetic testing for RET mutations. Because MTC does not respond to radioactive iodine, surgery is the main treatment, and post-operative calcitonin and CEA tracking guides follow-up.
Key Points
- MTC arises from C cells, which make calcitonin, not from the follicular cells that make thyroid hormone, so it behaves and is treated differently from papillary or follicular thyroid cancer.
- Two blood markers, calcitonin and CEA (carcinoembryonic antigen), help gauge how much cancer is present and how active it is.
- About 25% of cases are inherited, often as part of multiple endocrine neoplasia conditions, which is why genetic testing for RET mutations is recommended for everyone.
- Calcitonin and CEA levels should drop substantially after successful surgery, sometimes becoming undetectable; rising or persistently high levels prompt further imaging.
- Targeted therapies are available for spread or recurrence, especially in patients with RET mutations, when surgery did not remove all disease and further surgery is not feasible or safe.
Details Worth Noting
- Concrete instructions: Before surgery, check calcitonin and CEA blood levels and have genetic testing for RET mutations, which also informs whether relatives should be tested. Get a detailed neck ultrasound in clinic to check the central (middle) and lateral (side) lymph nodes. During the first surgery, remove the whole thyroid (total thyroidectomy), the central lymph nodes, and the lateral lymph nodes if ultrasound shows spread there, and remove any other concerning lymph nodes seen. After surgery, track calcitonin and CEA over time; if they stay high or rise again, obtain more imaging to look for regrowth or spread.
- Survival comparison cited by the speaker: 10-year survival for papillary thyroid cancer is about 97%, and higher for low-risk patients. For MTC, 10-year survival is about 95.6% if confined to the thyroid, about 75% if spread to lymph nodes, and closer to 40% if spread to other parts of the body.
- Radioactive iodine does not work for MTC, which is why surgical planning is emphasized and multiple surgeries are to be avoided.
- The speaker presents newer targeted therapies as not the first option, reserved for advanced or recurrent cases.
Bottom Line
Getting the first surgery right, guided by genetic testing, ultrasound, and calcitonin/CEA tracking, is the central factor in outcomes for medullary thyroid cancer.
