Based on a universal eradication of H. pylori in an offshore island (Matsu) with a high
prevalence of gastric cancer as well as premalignant gastric lesion, we first examined the
infection rate of H. pylori. Secondly, we evaluated the efficacy of clarithromycin-based
triple therapy with a levofloxacin-based rescue treatment. And thirdly, we tested the
hypothesis that whether the cure of H. pylori can reverse the premalignant gastric lesion.
Fourth, we determine the cost-effectiveness of this intervention. The gene-environment
interaction will be addressed regarding gastric cancer carcinogenesis. Finally, the incident
rate of gastric cancer would be followed in this cohort.