Prevalence of Helicobacter pylori infection in patients with precancerous changes and gastric cancer.

Several papers suggested a role for H. pylori infection in gastric cancer. We evaluated the prevalence of H. pylori infection in an endoscopic population of patients with gastric precancerous conditions and lesions by studying biopsies from 252 patients and recording the presence and degree of H. pylori infection. Patients were subgrouped as follows: chronic non-atrophic gastritis (CG), chronic atrophic gastritis (CAG), intestinal metaplasia (IM), epithelial dysplasia (ED) and gastric cancer (K). As control populations, patients with duodenal ulcer (DU) and patients with no endoscopic and histologic damage (CO) were investigated. H. pylori infection rate increased with age, but became significantly lower (P < 0.001) with the progression of gastric mucosal damage: DU 85%, CG 72%, CAG 58%, particularly in the antral type (39%), IM 63% overall, ED 44% and K 35%. The density of colonization showed the same trend (P < 0.001). Of the K patients, only 36% were H. pylori positive in the adjacent mucosa. Anti-H. pylori antibodies (IgG, IgA and IgM) were also tested. A concordance in the diagnosis between histology and serology was obtained in 82% of the cases. In our experience, H. pylori infection correlates inversely with the presence of gastric precancerous changes and cancer. A cautious interpretation of the epidemiological data regarding H. pylori infection and gastric cancer is therefore, in our opinion, mandatory.