Familial medullary thyroid cancer: clinical aspects and prognosis

To assess clinical features and long-term results of treatment of familial medullary thyroid carcinoma (FMTC).

Retrospective analysis of all patients with familial forms of MTC diagnosed between 1949-2000 and treated in our unit.

Fifty five patients (25 males, 30 females) were identified with at least two first-degree relatives affected by medullary thyroid cancer; 26 were classified as MEN 2A, 1 as MEN 2B and 28 as FMTC. Median age at diagnosis was 35 years (MEN 2A), 25 (MEN 2B) and 47.5 (FMTC). Median follow-up was 9 years (range: 4-24). Total or near-total thyroidectomy was performed in all patients and 11 received adjuvant external beam radiotherapy. Cause specific survival was 89% at 10 years and 77% at 20 years for MEN patients, 51% and 32% for those with sporadic MTC, and 46% and 26% for those with FMTC. In multivariate analysis, factors predicting survival were presence of metastases, nodal status and age at diagnosis.

Improved survival rates associated with familial types of MTC can be accounted for by the earlier stage at which disease is detected and the younger age at presentation. These observations emphasize the need for early detection in those at risk.