Gastrointestinal carcinoma in the Japanese of Hawaii: a status report.

The primary aim of the Japan--Hawaii Cancer Study was to identify factors that could explain the changes in cancer risk experienced by Japanese who migrated to Hawaii. Many investigations were conducted in this long-term prospective study since its inception in 1971. Among the findings that relate to gastrointestinal carcinoma were the following: 1) Bowel transit time does not appear to be related to the occurrence of large bowel cancer or to any of the benign conditions with which it is associated; 2) adenomatous and hyperplastic polyps, as well as diverticula, are much more prevalent among autopsy specimens from Japanese who had lived in Hawaii than of those in Japan; 3) adenomatous polyps and diverticula are positively associated with atherosclerosis in the necropsy population in Hawaii; 4) although the incidence of the diffuse histopathologic type of gastric cancer does not differ appreciably among the Japanese in Hawaii and Japan, the migrants have a significantly lower incidence of the intestinal type of stomach cancer; and 5) case-control studies indicated that the two conditions frequently associated with gastric carcinoma, i.e., gastric ulcer and intestinal metaplasia of the stomach, are associated with high salt intakes and adherence to the traditional Japanese diet.