The long-term risk of gastric cancer after the successful eradication of Helicobacter pylori

Background: We previously reported that eradication of Helicobacter pylori reduced the risk of developing gastric cancer in patients with peptic ulcer diseases. In the present study, we further followed up our patient group to investigate the occurrence and clinical features of gastric cancers that developed after cure of the infection. Methods: Prospective post-eradication evaluations were conducted on 1674 consecutive patients who had received successful H. pylori eradication therapy. The patients had undergone endoscopic examination before eradication therapy to evaluate peptic ulcers, background gastric mucosal atrophy, and H. pylori infection. After confirmation of cure of the infection, follow-up endoscopy was performed yearly. Results: The patients were followed for up to 14.1 years (a mean of 5.6 years). During the follow-up, gastric cancer developed in 28 of the 1674 patients as long as 13.7 years after the cure of H. pylori infection. The risk of developing gastric cancer was 0.30% per year. Histologically, 16 of the gastric cancers were the intestinal type and 12 were the diffuse type; the risk of each cancer type was 0.17 and 0.13% per year, respectively. There was no significant inflammatory cell infiltration in the background gastric mucosa at the time the cancers were recognized. Conclusion: There is a risk of developing gastric cancer of both the intestinal and diffuse types even after the cure of H. pylori infection and extinction of gastric inflammation. It is important to inform patients about the risk of gastric cancer after eradication therapy and offer them surveillance endoscopy.