Unusual features of thyroid carcinomas in Japanese patients with Werner syndrome and possible genotype-phenotype relations to cell type and race.

BACKGROUND Werner syndrome (WS), an autosomal recessive disease characterized by premature aging, has a high frequency of association with six rare neoplasms in Japanese patients, and only four of these neoplasms also occur excessively in whites. Several differ from what is usual in their epidemiology and/or histology. Described in this article are peculiarities in the occurrences of follicular and papillary thyroid carcinomas among Japanese patients and the possible genotype-phenotype relations pertaining to cell types and the absence of excess thyroid carcinoma occurrence in whites with WS. METHODS Epidemiologic features of 23 histologically diagnosed thyroid carcinomas from a series of 150 cancers in 845 Japanese patients with WS were compared with those of 19,446 tumors in a Japanese national registry of thyroid carcinomas from 1977-1991. Germline mutations had been determined by molecular studies of peripheral blood. RESULTS The average age of patients with thyroid carcinoma was 39 years for those with WS and 49 years for the registry patients. The female-to-male ratios were 2.3:1 and 6.6:1, respectively. The rates of occurrence of papillary, follicular, and anaplastic carcinomas were 35%, 48%, and 13% for Japanese patients with WS and 78%, 14%, and 2% in the general Japanese population. All four cases of follicular carcinoma had germline mutations of the WS gene in the C-terminal region, and the germline mutation for the only papillary carcinoma was in the N-terminal region. CONCLUSIONS This study suggests two possible WS genotype-phenotype relations. One concerns thyroid carcinoma histology; the other concerns frequent mutations that occur in the C-terminal region in Japanese patients, but not in white patients, with WS. These may account for the excess thyroid carcinoma occurrence among Japanese.