Medullary carcinoma of the thyroid--therapeutic strategy derived from fifteen years of experience.

BACKGROUND

The purpose of this investigation was to analyze our experience with patients treated for medullary carcinoma of the thyroid to identify prognostic factors and to develop a stage-related treatment strategy that might improve cure rates.

METHODS

Between 1970 and 1985 a total of 40 patients with medullary thyroid carcinoma were treated (21 women, 19 men; mean age +/- SEM; 40 +/- 3 years; mean follow-up, 82 +/- 12 months). Initial operation involved total thyroidectomy (28 patients), subtotal resection (11 patients), and a lobectomy (1 patient). The initial lymph node dissection generally consisted of a selective removal of enlarged nodes. Unilateral neck dissection was performed in six cases. Secondary operation for recurrent disease was necessary in 26 patients.

RESULTS

At the end of the follow-up period 10 patients were tumor free, 12 patients were scheduled for further treatment, six patients suffered from persistent but clinically occult disease, and 12 patients had died (mean survival time, 68 +/- 7 months). The paramount prognostic factor was the absence or presence of lymph node involvement at the time of primary operation (p = 0.011). Patients with distant metastases died within 2 years of diagnosis. Women, patients younger than 40 years of age, and those elicited by familial screening programs exhibited increased survival times.

CONCLUSIONS

Because of the prognostic and therapeutic importance we recommend the total thyroidectomy with a complete dissection of the central lymph node compartment as primary treatment. Patients with lymph node involvement or elevated serum calcitonin levels should subsequently be treated by a modified radical neck dissection of the lateral compartments.