Calcitonin and carcino-embryonic antigen in the follow-up of patients with medullary carcinoma of the thyroid.

Nineteen patients who have had medullary carcinomas of the thyroid have been followed up at the Royal Marsden Hospital. All had nodal involvement. Postoperative unprovoked serum calcitonin assays have been performed. Four patients had incomplete excisions of their tumours and these had the highest postoperative levels. Two died within 3 years, one has stable disease 8 years later and one remains well 13 years later. Four patients had postoperative calcitonin assays of over 100 ng/ml but had no clinical evidence of remaining disease. Only one has died (7 years later), the others remaining well 10, 10 and 3 years later. Four patients died of their disease and all had assays of over 200 ng/ml, before death. Slightly raised postoperative assays were found in all the other patients, but these have not significantly altered. These patients had good prognoses. Three patients also had regular carcino-embryonic antigen (CEA) assays and the value of this is discussed.