Possible role of Helicobacter pylori infection in early gastric cancer development

BACKGROUND: Gastric cancer is the most frequently diagnosed malignancy in Japan. The possible relationship between Helicobacter pylori infection and gastric cancer in Japan was evaluated. METHODS: H. pylori infection was identified by the presence of anti-H. pylori IgG. The frequency of H. pylori infection was compared in 213 patients with gastric cancer and the same number of asymptomatic control subjects matched for age and sex. RESULTS: The presence of IgG antibody to H. pylori was significantly more prevalent (P < 0.001) in those with gastric cancer compared with asymptomatic control subjects (88.2% versus 74.6%). H. pylori positive rates were significantly greater in patients with the intestinal type (90.4%, P < 0.001) and diffuse type (86.4%, P < 0.05) of gastric cancer than in control subjects. Ninety-three percent of the patients with early gastric cancer tested positive for H. pylori (P < 0.001 compared with control subjects), whereas no significant difference was observed between those with advanced gastric cancer and control subjects. The intestinal type of early gastric cancer showed only the significantly increased frequency of high titer (optical density > 1.50) of H. pylori IgG antibody (P < 0.001) compared with control subjects without cancer. CONCLUSIONS: These results suggest that H. pylori infection may be associated with the development of early gastric cancer in Japan.