The extent of surgery for thyroid medullary cancer

Evaluation of the impact of the extent of primary surgery and reintervention on the outcome of patients with medullary thyroid carcinoma.

Seventy-two patients with medullary thyroid carcinoma (MTC) were surgically treated between 1967 and 1992.

Fifty-five cases were sporadic, 5 patients had MEN 2A, 4 MEN 2B syndrome and 8 familial non-MEN MTC; 1 patient had stage I disease, 30 patients stage II, 36 stage III and 5 stage IV. Sixty-four had their initial treatment at our center, and 8 came for subsequent treatment. At first treatment, 8 patients were subjected to partial thyroidectomy, 10 to total thyroidectomy, 53 to total thyroidectomy with neck dissection, and 1 to only radical neck dissection; postoperative serum calcitonin (Ct) levels returned to normal in 3, 6 and 27 patients, respectively. In the patient with only radical neck dissection, Ct levels remained elevated. No patient with Ct normalization after surgery became responsive to pentagastrin in the follow-up. Thirteen patients had a reoperation due to nodal relapse. At a mean follow-up of 5.7 years (6-252 months), the 10-year survival rate was 84.5% with a significant difference between patients under and over 40 years of age (96.4 vs 57%), between stage I-II (100%) and stage III, IV (83.8%, 0% respectively). At the last follow-up, 36 (50%) patients were alive and disease free and 26 were alive with disease (15 with distant metastases). Of the 10 deaths, 7 were due to tumor recurrence, 3 to 120 months after surgery.

Data suggest that an earlier diagnosis rather than more extensive surgery could improve survival and reduce recurrences. However, the least treatment required is total thyroidectomy plus central neck and upper mediastinum clearance and in addition, according to the extent of nodal involvement, mono- or bilateral neck dissection. To avoid ineffective reoperation due to distant (mainly liver) micrometastases, persistent residual microscopic disease requires a more aggressive restaging.