PROGNOSTIC VALUE OF EARLY POSTOPERATIVE CALCITONIN LEVEL IN MEDULLARY-THYROID CARCINOMA

Aims: Serum calcitonin (CT) assay is commonly used in the diagnosis an d follow-up of medullary thyroid carcinoma (MTC). The aim of this stud y was to ascertain whether serum CT levels, measured in the first few days after surgery, could be used to evaluate the efficacy of treatmen t. Methods: A group of 33 patients was studied. In all patients the fo llow-up was more than 20 months. Results: Preoperatively basal CT seru m levels were high in all patients. Twenty-four hours after surgery CT serum levels dropped to within the normal range in 8 patients and 72 hours after operation in 7 others. In this group 1 patient was at stag e I, 11 at stage II and 3 at stage III. Basal and pentagastrin stimula ted CT levels continued to be in the normal range in these 15 patients 6 and 12 months after surgery and at the subsequent year by follow-up visits. No clinical or radiological evidence of disease was found dur ing the follow-up in this group. In the other 18 patients CT was reduc ed but still high 72 hours after surgery; 6 months later basal serum C T levels continued to be elevated or responsive to pentagastrin stimul ation. In this group restaging showed tumor relapse in the thyroid bed in 2 patients, cervical lymphadenopathy in 11, and distant metastases (bone, liver) in a Conclusions: Immediate postoperative CT serum leve ls seem to be the most useful index to evaluate the efficacy of surgic al treatment and the presence of residual neoplastic tissue.