[The roles of H. pylori infection and K-ras gene mutation in gastric carcinogenesis].

To elucidate the significance of K-ras gene mutations in gastric carcinogenesis, we examined the mutations in gastric cancers and in Helicobacter pylori-associated chronic gastritis(H. pylori-CG). In gastric cancers, K-ras gene mutations were detected in intestinal type cancers, but not in diffuse type cancers. K-ras gene mutations in H. pylori-CG were significantly more frequent in gastric cancer patients than in cancer-free patients. These data suggest that K-ras gene mutations may be involved in the early stages of gastric carcinogenesis of the intestinal type. Recently, Uemura, et al. reported that H. pylori eradication suppressed gastric cancer development(Cancer Epidemiol Biomarkers Prev, 1997; N Engl J Med, 2001). Further examination is necessary to clarify the mechanism of suppression of gastric cancer development after H. pylori eradication.