Research has linked Helicobacter pylori causes gastric cancer, but it is still controversial that whether H. pylori eradication therapy is effective in primary prevention of gastric cancer.
This is especially important for Yamagata Prefecture, a region of Japan with the second highest incidence of gastric cancer in the world.
A research article to be published on September 14, 2009 in the World Journal of Gastroenterology addresses this question. A research team led by Dr. Katsuhiro Mabe from Division of Gastroenterology of KKR Sapporo Medical Center did a multicenter, prospective cohort study in residents of Yamagata Prefecture between 2000 and 2007. They compared the incidence of gastric cancer between patients with H. pylori-positive peptic ulcer who underwent H. pylori eradication (eradication group) or conventional antacid therapy (non-eradication group) at the patients' discretion. A total of 4133 patients with a mean age of 52.9 years were registered, and 56 cases of gastric cancer were found over a mean follow-up period of 5.6 years. The sex- and age-adjusted incidence ratio of gastric cancer in the eradication group, as compared with the non-eradication group, was 0.58 (95% CI: 0.28-1.19). The ratios by follow-up period of < 1 year, 1-3 years, and > 3 years were 1.16 (0.27-5.00), 0.50 (0. 17-1.49), and 0.34 (0.09-1.28), respectively, which indicated that longer follow-up tended to be associated with better prevention of gastric cancer. There was no significant difference in incidence of gastric cancer between patients with and without successful eradication therapy. However, among patients with duodenal ulcer, which is more common in younger individuals, the incidence of cancer was significantly less in those with successful eradication.