[Changes of gastric mucosa histopathology after Helicobacter pylori eradication].

Objective: To investigate the relationship between Helicobacter pylori (Hp) infection and gastric cancer through the changes of gastric mucosa histopathology within 5 years after Hp eradication in Hp-positive subjects in the high incidence region of gastric cancer.

Methods: One thousand and six adults were selected from general population in Yantai, Shandong Province, the high incidence region of gastric cancer. Gastroscopy and CLO test were performed in all subjects. Biopsy samples from the gastric antrum and body were obtained for histology and assessment of Hp infection. All the Hp-positive subjects were then randomly divided into two groups: treatment group receiving OAC triple therapy and placebo as controls. These subjects were endoscopically followed up in the second and fifth year. In this article, we compared the endoscopic appearance and histology of the biopsy specimens from the same site obtained at the first and final visit. Statistical analysis was done by chi(2) test.

Results: All the 552 Hp-positive subjects were randomly divided into treatment group or control group, 276 in each. During the five-year follow-up, the number of patients who continued to be negative or positive for Hp was 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 between the biopsy specimens from the antrum (P = 0.105) and body (P = 0.084) in both groups. But the proportion of atrophy and intestinal metaplasia in the antrum was much higher than that in the body (P = 0.000). (2) The severity and activity of inflammation in both the antrum and body were markedly reduced after Hp eradication (P = 0.000). (3) Within the five years after Hp eradication, intestinal metaplasia in the antrum regressed or had no progression, while the proportion of intestinal metaplasia in the Hp-positive group increased significantly (P = 0.032). (4) After Hp eradication, the atrophy in both the antrum and body had no significant regression. P value was 0.223 and 0.402, respectively.

Conclusions: Hp 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, continued Hp infection leads to progressive aggrevation of atrophy and intestinal metaplasia.