Seventeen-year effects of eradicating Helicobacter pylori on the prevention of gastric cancer in patients with peptic ulcer; a prospective cohort study.

Background: We previously reported that eradication of Helicobacter pylori in our cohort of patients with peptic ulcer disease reduced their risk of developing gastric cancer to approximately one-third after a mean follow-up period of 3.4 years (up to 8.6 years). We have now followed these patients for a longer period.

Methods: A total of 1,222 consecutive patients with peptic ulcer diseases who completed more than 1-year follow-up after receiving H. pylori eradication therapy were followed with annual endoscopic surveillance for a mean of 9.9 years (as long as 17.4 years).

Results: H. pylori infection was judged cured in 1,030 patients (eradication-success group) but persisted in 192 (eradication-failure group) after initial eradication therapy. In the eradication-failure group, 114 patients received re-treatment at a mean of 4.4 years after the start of follow-up, and 105 of these were cured of infection. Gastric cancer developed in 21 of the 1,030 patients in the eradication-success group and in nine of the 192 in the failure group (p = 0.04). The risk of developing gastric cancer in the eradication-success group (0.21 %/year) was significantly lower than that in the failure group (0.45 %, p = 0.049). The longest interval between the initial H. pylori eradication and the occurrence of gastric cancer was 14.5 years in the eradication-success group and 13.7 years in the eradication-failure group.

Conclusions: A prophylactic effect for gastric cancer persists for more than 10 years after H. pylori eradication therapy, but we should be aware that cancer can develop even after that interval.