The purpose of this study is to determine whether Helicobacter pylori eradication could reduce the new tumor development after endoscopic resection of gastric tumor.

The association between Helicobacter pylori infection and development of gastric cancer has been established by epidemiologic studies. Conversely, eradication of H. pylori showed no significant reduction of the incidence of gastric cancer in a large-scale, double-blind, randomized controlled trial. Eradication of H. pylori to prevent cancer was only effective in the subgroup without precancerous lesions (i,e, dysplasia, intestinal metaplasia, and atrophy). In contrast, randomized prospective study in Japan showed that H. pylori eradication after endoscopic resection of early gastric cancer significantly reduced metachronous gastric cancer. To solve this conflicting issue is critical because gastric cancer is the second leading cancer incidence worldwide, particularly Korea, Japan, and China have highest cancer incidence, and its incidence might decrease by H. pylori eradication treatment.

With respect to therapeutic modality, endoscopic resection for early gastric cancer is currently the established treatment of choice in Korea and Japan because it has been proven to be both minimally invasive and effective in the curative treatment of early gastric cancer.

Endoscopic resection has also been performed in the gastric dysplasia because dysplasia has to some extent malignant potential although firm evidence is lacking. In comparison with surgical resection, endoscopic resection conserves remnant stomach. Accordingly, patients treated with endoscopic resection have higher possibility for metachronous gastric cancer than those treated with surgical resection.

So far, it has not yet been clearly established whether H pylori eradication for gastric tumors (early gastric cancer and gastric dysplasia) could reduce metachronous cancer. We performed randomized controlled, open-label trial on the effect of new cancer development after H pylori eradication for gastric tumors.

Inclusion Criteria:

• H pylori infected patients with gastric low-grade dysplasia, high-grade dysplasia, and early gastric cancer
• Gastric tumor is completely removed through endoscopic resection.

Exclusion Criteria:

• Patients underwent gastrectomy before enrollment
• patients underwent endoscopic resection before enrollment
• Previous history of eradication for H. pylori
• Pregnancy
• Aged <20 yr old or aged >75 yr old
• Patients underwent additional gastrectomy due to incomplete endoscopic resection