Long term prognosis of medullary thyroid carcinoma in 39 patients

Background and Aims: Thyroidectomy and radical cervical lymph node dissecti on have been suggested as primary and secondary operations aimed at achievi ng biochemical cure in cases of medullary thyroid carcinoma (MTC). The purp ose of this study was to find out behaviour of MTC in long-term follow-up, and to estimate possible difference in biological virulence between sporadi c MTC and MTC in MEN2A. Materials and Methods: From 1967 through 1994, 39 patients with MTC, includ ing 9 patients with hereditary disease, were operated on at the Second Depa rtment of Surgery, Helsinki University Central Hospital. Enlarged lymph nod es were dissected selectively. The main outcome measure was carcinoma-speci fic survival. Results: In sporadic MTC, ten-year carcinoma-specific survival was 57.9% (9 5% CI 39.1%-76.7%) and ten-year survival after reoperation due to lymphatic node recurrence was 51.4% (CI 18.7%-84.2%). The presence of distant metast ases at diagnosis (p = 0.0001) and extrathyroidal growth of the primary tum or (p = 0.0008) were independent predictors of carcinoma-specific survival in the Cox model. The risk ratio of sporadic MTC to MTC in MEN2A was 5.40 ( CI 0.67-43.2) after adjusting the survival time for the size of the primary tumor. Conclusion: Distant metastases and the local extrathyroidal extent of the p rimary tumor have a significant effect on the prognosis of MTC, lymphatic n ode metastases and other clinical factors being less important. The biologi cal virulence of sporadic MTC may be clinically significantly higher than t hat of MTC in MEN2A.