Changes in the histologic types of gastric carcinoma in Japan.

The changes in histologic types of gastric carcinoma in Japan in recent years was studied utilizing the 4147 cases surgically resected at the Cancer Institute Hospital, Tokyo, from 1955 to 1974. All carcinomas were classified as either well-differentiated or poorly differentiated, and the ratio of the former to the latter (WPR) was calculated for the first decade (1955-1964) and the second decade (1965-1974). A decline in the WPR was observed, although the difference was not statistically significant. However, when the material was subdivided according to the site of the tumor in the stomach, a decrease in the WPR was markedly visible in the area designated as Fl-area, i.e., a part of the fundic area susceptible to intestinalization. When limited to this area, the difference was statistically significant (P less than 0.05).