THE EXTENT OF SURGERY FOR THYROID MEDULLARY CANCER

Aims: Evaluation of the impact of the extent of primary surgery and re intervention on the outcome of patients with medullary thyroid carcino ma. Methods: Seventy-two patients with medullary thyroid carcinoma (MT C) were surgically treated between 1967 and 1992. Results: Fifty-five cases were sporadic, 5 patients had MEN 2A, 4 MEN 2B syndrome and 8 fa milial non-MEN MTC; 1 patient had stage I disease, 30 patients stage I I, 36 stage III and 5 stage IV. Sixty-four had their initial treatment at our center, and 8 came for subsequent treatment. At first treatmen t, 8 patients were subjected to partial thyroidectomy, 10 to total thy roidectomy, 53 to total thyroidectomy with neck dissection, and 1 to o nly radical neck dissection; postoperative serum calcitonin (Ct) level s returned to normal in 3, 6 and 27 patients, respectively. In the pat ient with only radical neck dissection, Ct levels remained elevated. N o patient with Ct normalization after surgery became responsive to pen tagastrin 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 1 0-year survival rate was 84.5% with a significant difference between p atients 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 foll ow-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. Conclusions: D ata suggest that an earlier diagnosis rather than more extensive surge ry could improve survival and reduce recurrences. However, the least t reatment required is total thyroidectomy plus central neck and upper m ediastinum 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.