THYROID-CARCINOMA IN JAPAN AND THE WEST - SIMILARITIES AND DIFFERENCES

Geographic or ethnic differences in the incidence of thyroid carcinoma , as well as in the histologic distribution of thyroid carcinoma betwe en Japan and Western countries, have been described but are still uncl ear. The recent establishment of histologic criteria for the diagnosis of thyroid carcinoma by the WHO committee has facilitated the compari son of clinicopathological data of patients with thyroid carcinoma all over the world. The aim of the present review article is to clarify t he epidemiological and clinicopathological differences of thyroid carc inoma between Japan and Western countries. We found recently no signif icant differences in the incidence, mortality, and histologic distribu tion of thyroid carcinoma between Japan and Western countries; this wa s contrary to our expectation. This is likely attributable to westerni zation of the Japanese diet, standardized medical levels, and internat ional standardization of histologic criteria of thyroid carcinoma.