<i>Helicobacter pylori</i> eradication prevents the development of gastric cancer – results of a long‐term retrospective study in Japan

Summary Aim This large‐scale study was designed to investigate the incidence of gastric cancer after Helicobacter pylori ( H. pylori ) eradication in Japan. Methods This study was a retrospective multicentre study performed at 23 centres in Japan. Patients in whom H. pylori had been successfully eradicated and those in whom the infection persisted were entered into the study if they had undergone an upper endoscopic examination at least once a year for five consecutive years. The incidence rates of gastric cancer during follow‐up were compared between those whose infections had been successfully eradicated and those with persistent H. pylori infection. Results Three‐thousand twenty‐one patients were enrolled. The median follow‐up was 7.7 years for the infected group and 5.9 years for the eradicated group. Gastric cancer developed in 23 (1%) of those in whom H. pylori was successfully eradicated compared with 44 (4%) of those with persistent H. pylori infection (OR = 0.36; 95% CI = 0.22–0.62). Conclusion This large‐scale retrospective clinical study in Japan, which has a high mortality rate for gastric cancer, indicates that H. pylori eradication may prevent the development of gastric cancer.