Medullary thyroid carcinoma: importance of serial serum calcitonin measurement.

Thirty-two patients with medullary carcinoma of the thyroid (MCT) were studied before and after therapy. Sixteen patients had familial and 16 had the sporadic type of disease. The groups differed in several features: Patients with sporadic disease were older at diagnosis and presented with enlargements in the thyroid or lymph nodes, and one patient had neuromata; in the familial group the disease was more often bilateral and was associated at times with the MEA syndrome (parathyroid adenoma or pheochromocytomas, or both). The immunoreactive serum calcitonin (CT) level was measured before and after some form of therapy in all 32 patients. Our investigations showed: 1) Delaying treatment was clearly detrimental in this progressive disease; 2) The most effective therapy was surgery, while radiotherapy and chemotherapy were less effective; 3) Postoperatively, the CT level usually fell sharply, when the disease was thought extirpated, but the lowest nadir might be reached at from 1 month to 6 years; 4) In all such patients the CT level eventually rose from the postoperative nadir; 5) Patients with no clinical or radiological evidence of disease, had high CT levels for a mean of 3 years of observation; 6) A marked rise of CT levels in three patients preceded metastases and death; 7) Patients with abdominal, particularly liver disease had the highest CT levels; and 8) Patients who died had relatively high CT levels, corresponding in general with the extent of disease.