Changes in histopathological features of gastric carcinoma over a 26-year period (1965-1990)

Epidemiological study has shown that the incidence rate of gastric carcinoma in Japan has declined recently. To explore the factors that have influenced this decrease, the changing pattern in clinico-pathological features of gastric carcinoma was studied from the epidemiological point of view. The 5,015 cases of gastric carcinoma treated with gastrectomy at Aichi Cancer Center Hospital from 1965-1990 were divided into two histopathological types: the well-differentiated and other types. Proportional distribution was compared over the three different periods (1965-1973, 1974-1982, 1983-1990) according to the clinico-pathological features of the gastric carcinoma, i.e., sex, age, lesional location, etc. The recent relative decline of gastric carcinoma is due mainly to the decline of carcinoma of the well-differentiated type. This decline has been highly correlated to the decline in carcinoma of the antrum, which has been the most common in Japan. This changing pattern of clinicopathological features of Japanese gastric carcinoma might be affected by the change of exposure patterns to epidemiological factors, i.e., a Westernizing diet.