| [ Summary ] |
The causal relationship between H. pylori infection and gastric cancer has been studied intensively. It has been proved in animal or clinical studies that the progression of gastric precancerous condition is accelerated by H. pylori infection. In addition, the animal experiments using Mongolian gerbils showed that H. pylori has promoting or initiating activity. Further more, it has been reported in human beings that H. pylori eradication may reverse the precancerous condition and inhibit the newly cancer in remnant stomach after the EMR. These data suggest that H. pylori infection is an important avoidable risk factor of gastric cancer.
However, it is well known the discrepancy between the prevalence of H. pylori and the incidence of gastric cancer in the several, especially Asian countries. The interaction among 3 factors, bacterial, host and environmental factors may be involved mutually in gastric carcinogenesis. To determine whether H. pylori eradication is essential or not for the prevention of gastric cancer, the intervention study is need. Recently, the intervention studies in Columbia and China have reported that H. pylori has a close association with the development of gastric cancer. However, this kind of study should be conducted in each country due to the difference of race, life style and so on. The Japanese study (JITHP) started in 1994 has finished and its analysis is ongoing. |