CURRENT STATUS OF INHERITED MEDULLARY-THYROID CARCINOMA IN JAPAN

We conducted a large-scale nationwide questionnaire survey to characte rize the clinical course of inherited medullary thyroid carcinoma (MTC ). Out of a total of 634 MTC patients (M:F ratio 1:2.5), 175 patients had multiple endocrine neoplasia (MEN) 2A, 49 had familial non-MEN med ullary thyroid carcinoma (FMTC), 20 had MEN 2B, and 390 had sporadic M TC. Median age at the time of diagnosis was 40.3, 43.0, 26.5 and 48.5 years, respectively. Total thyroidectomy plus modified neck dissection (MND) was the most common operation. The 5-year survival rates were 9 6.9% in MEN 2A, 100% in FMTC, 73.8% in MEN 2B, 90.8% in sporadic MTC. The outcome in order from best to worst was: FMTC, MEN 2A, sporadic MT C, and MEN 2B, with MEN 2B considered the most aggressive type.