OBJECTIVESTo investigate the relationship between H. pylori infection, gastric cancer and other gastric diseases through the changes in gastric mucosa and the status of different gastric diseases within 5 years after H. pylori eradication in H. pylori-positive subjects in a high incidence region of gastric cancer.

METHODSOne thousand and six adults were selected from the general population in Yantai, Shandong province, a high incidence region for gastric cancer in China. Gastroscopy and Campylobacter-like organism (CLO) testing were performed on all subjects. Biopsy samples from the gastric antrum and body were obtained for histology and assessment of H. pylori infection. All H. pylori-positive subjects were then randomly divided into two groups: treatment group receiving Omeprazole Amoxicillin Clarythromycin (OAC) triple therapy and placebo as controls. These subjects were endoscopically followed up in the second and fifth year. We compared the endoscopic appearance and histology of the biopsy specimens from the same site obtained at the first and last visits.

RESULTSAll 552 H. pylori-positive subjects were randomly and evenly divided into treatment group or control group. During the five-year follow-up, the numbers of patients who continued to be negative or positive for H. pylori were 161 and 198, respectively. Statistical analysis revealed that: (1) At the initial visit, there were no significant differences in the severity and activity of inflammation, atrophy and intestinal metaplasia between the biopsy specimens from the antrum and body respectively in both groups. (2) The severity and activity of inflammation in both the antrum and body were markedly reduced after H. pylori eradication (P = 0.000). (3) Within five years after H. pylori eradication, intestinal metaplasia in the antrum either regressed or had no progression, while the proportion of intestinal metaplasia in the H. pylori-positive group increased significantly (P = 0.032). (4) After H. pylori eradication, the atrophy in both the antrum and body had no significant regression. The P value was 0.223 and 0.402, respectively.

CONCLUSIONSH. pylori eradication results in remarkable reduction in the severity and activity of chronic gastritis, marked resolution of intestinal metaplasia in the antrum. On the other hand, continuous H. pylori infection leads to progressive aggravation of atrophy and intestinal metaplasia.