BACKGROUND/AIMS There have been few reports comparing pre and postoperative prevalence of Helicobacter pylori infection and gastritis in patients with gastric cancer surgery.

METHODOLOGY Seventy patients with primary gastric cancer were identified to be infected with Helicobacter pylori preoperatively and tested for Helicobacter pylori infection after subtotal gastrectomy. We analyzed changes in Helicobacter pylori infectivity and histological features of gastric mucosa.

RESULTS The overall spontaneous regression rate of Helicobacter pylori infection was 38.6% (27/70). The mean time between surgery and follow-up tests was 1.02±0.5 years. The activity and chronic inflammation scores were significantly decreased in regression group. In non-regression group, there was no significant difference in activity scores, but the chronic inflammation score was significantly increased. There were no significant changes in atrophic gastritis and intestinal metaplasia scores in either group. The grade of Helicobacter pylori infection was significantly decreased in non-regression group.

CONCLUSIONS The spontaneous regression rate of Helicobacter pylori infection after subtotal gastrectomy was 38.6% (27/70), it occurred in larger scale of patients and it occurred earlier (1.02±0.5 years) than in previous studies. We suggest that further prospective study on spontaneous regression rate of Helicobacter pylori infection after subtotal gastrectomy and its mechanism is needed in the future.