Clinical characteristics of hereditary and sporadic medullary thyroid carcinoma.

OBJECTIVE: To study the clinical characteristics and outcomes of the hereditary medullary thyroid carcinoma (HMTC) and the sporadic medullary thyroid carcinoma (SMTC). METHODS: The clinical data of 78 patients with medullary thyroid carcinoma who underwent surgery in our hospital between July 1980 and May 2011 were retrospectively analyzed. RESULTS: Of these 78 patients, there were 23 HMTC cases and 55 SMTC cases. The HMTC group was significantly younger age of onset [(36.4±13.5) years vs. (46.6±11.2) years, P<0.01] and a lower pre/post-operative serum calcitonin levels [(850.4±110.20) ng/L vs. (1450.4±118.3) ng/L, P<0.01 and (410.8±133.2) ng/L vs. (1585.4±129.5) ng/L, P<0.01] than the SMTC group. In addition, the mean tumor diameter was also significantly smaller in the HMTC group (14.3 mm vs. 21.0 mm in SMTC group, P<0.05). Tumor multifocality was seen in a significantly higher proportion of HMTC cases compared with the SMTC cases (56.6% vs. 29.1%, P<0.05). The overall 10-year survival was 100% in HMTC group and 80.2% in SMTC group (P<0.05). CONCLUSION: HMTC has a better prognosis than SMTC.