Histological analysis of gastritis and Helicobacter pylori infection in patients with early gastric cancer: a case-control study.

Background and Aims: Infection with Helicobacter pylori is associated with an increased risk of gastric adenocarcinoma. However, most patients with H. pylori infection will not develop gastric cancer. The aims of the present study were to examine which histological features, including H. pylori infection, would increase the risk of gastric cancer using a case-control study. Methods: Three gastric biopsy specimens were taken from 72 patients with early gastric cancer and 72 age- and sex-matched control subjects. The grade of gastritis was examined according to the updated Sydney System. The presence of H. pylori infection was determined by serology and histology. Odds ratio (OR) of developing gastric cancer was calculated for H. pylori positivity and histological features using conditional logistic regression. For patients with H. pylori infection, histological features in cancer patients and control subjects were compared. Results: The OR of the presence of mononuclear cell infiltration in the corpus and intestinal metaplasia in the angulus were significantly elevated. The grade of mononuclear cell infiltration in the corpus and antrum was significantly higher in both types of cancer patients than controls. Glandular atrophy and intestinal metaplasia were increased in patients with intestinal-type cancer in the angulus and antrum. Bacterial density in the corpus and polymorphonuclear cell infiltration in the antrum were increased in patients with diffuse-type cancer. Conclusions: Severe chronic gastritis induced by H. pylori infection seems to be associated with diffuse-type gastric cancer. Glandular atrophy and intestinal metaplasia, which occur in gastric mucosa with chronic inflammation, are significantly associated with intestinal-type cancer.