[The relationship between stomach cancer and intestinal metaplasia of the gastric mucosa and food intake].

The natural history of intestinal metaplasia of gastric mucosa was studied in 414 rural inhabitants; 213 males and 201 females, from Chokai Village in Akita Prefecture in the northeast part of Japan's main island of Honshu. The subjects were examined by a mobile gastrointestinal unit and were biopsied at eight standard points of the gastric mucosa. The specimens were examined histologically, and were divided into 4 grades. The metaplasia index (MI) was adopted as a quantitative expression of the severity of intestinal metaplasia of the gastric mucosa. The MI of the three areas of the village were compared with the different incidences of stomach cancer. The following results were obtained: in gastric mucosa. The average values of the MI among the male population were highest at the high-risk area, low at the low-risk area and intermediate at the moderate-risk area of gastric cancer. Whereas, the values among females showed no differences in these three areas. The risks for stomach cancer also were almost equal. These phenomena would show a very close relationship between intestinal metaplasia and the incidence of stomach cancer. There was a positive correlation (p less than 0.01) between MI and the detection rates of stomach cancer by a mass screening examination in the areas. Study of food intake and especially the salt consumption among the three areas showed a close relationship with intestinal metaplasia. Certain foods seemed to relate to intestinal metaplasia and eventually to stomach cancer. The conclusion was drawn that the development of intestinal metaplasia could be prevented by the improvement of environmental factors especially by that of food intake. Thus, the reduction in the incidence of stomach cancer also would be possible.