[Diagnosis and treatment policy in familial thyroid cancer]

Thirty-two cases of hereditary medullary thyroid carcinoma (HMTC) and 95 sporadic HMTC (SHMTC), 44 familial papillary TC (FPTC), and 172 sporadic cases were comparatively analyzed to improve the diagnosis and treatment of familial thyroid cancer. A hundred and one DNA samples from patients with MTC and their relatives were examined. BRAF and RET/PTC gene mutations were investigated in 6 patients with FPTC. The frequencies of familial TC, HNTC, and FPTC were 6 6, 26.5, and 4.3%, respectively. The mean age of patients with HMTC and SHMTC was 30.J±13.6 and 46.3±J3.1 years, respectively (p < 0.0001); tumor multicentricity was 87.5 and 36.8% (p < 0 0001) and bilaterality was 87.5 and 0%, respectively (p < 0.001). Inheritable RET mutations were detected in 16 families. Eight asymptomatic carriers of RET mutations were revealed; 3 of them underwent preventive thyroidectomy. There was the commonest (63.6%) codon 634 mutation in which the earliest manifestation and aggressive course of the disease were observed. The efficiency of screening for type 2 multiple endocrine neoplasia syndrome Increased by 1.8 times (from 31.2 to 51.2%). In the mother and daughter with FPTC, silent mutation was found in codon 891 of RET gene exon 15. Genetic examination of the relatives of patients with HMTC made it possible to diagnose the disease at its early stage and to perform preventive surgical treatment. The aggressiveness of HMTC makes it necessary to make total thyroidectomy. The absence of differences in the clinical course of familial and sporadic PTC predetermines uniform treatment policy.