Potential absence of prognostic implications of severe preoperative hypercalcitoninemia in medullary thyroid carcinoma.

OBJECTIVE

To evaluate preoperative hypercalcitonine-mia further as a marker of prognosis in patients with medullary thyroid carcinoma (MTC).

METHODS

We reviewed the clinical and laboratory data in six patients (four men and two women, 39 to 76 years old)--three with sporadic MTC, one with familial MTC, and two with multiple endocrine neoplasia type 2A--who had preoperative basal serum calcitonin levels of 400 to 16,000 pg/mL (normal, 0 to 19). Pentagastrin stimulation was performed in patients who had preoperative basal calcitonin levels less than 1,000 pg/mL, and responses ranged from 2,600 to 8,500 pg/mL. Thyroidectomy revealed intrathyroidal MTC in four patients; MTC and nodal metastatic lesions were present in two. The tumor cells were immunoreactive with anti-calcitonin immunoperoxidase staining.

RESULTS

Serum calcitonin and carcinoembryonic antigen levels were normal postoperatively. In serial postoperative evaluation during a follow-up period of 2 to 9 years, stimulated peak plasma calcitonin levels after pentagastrin or calcium infusion were normal (in five patients) or near normal (in one patient), without clinical evidence of recurrent disease. The two patients with nodal metastatic disease have had normal calcitonin levels during a mean duration of follow-up of approximately 3 years.

CONCLUSION

Pronounced preoperative hypercalci-toninemia does not necessarily preclude a favorable short-term outcome in patients with MTC.