The aim of this study is to define the role of H. pylori eradication in the prevention of gastric cancer and its precursors in the context of a population-based endoscopic screening program.

Despite the decreasing incidence observed in the US and West European countries, gastric cancer is still an important global public health problem, especially in East Asian countries, where the burden of the disease is substantial. In the Republic of Korea, gastric cancer remains the leading cause of cancer in men and the fourth most common cancer in women. There is sufficient epidemiological and experimental evidence supporting a causal link between bacterial infection with H. pylori and gastric cancer development. However, evidence from clinical trials on the efficacy of H. pylori eradication with antimicrobial therapy to reduce the risk of gastric cancer is still limited. In addition, the beneficial or deleterious health impact of mass eradication at the population level has not been defined. In Korea, the prevalence of H. pylori infection in adults is still relatively high (~60%, >16 years old), and despite important reductions in mortality attributed to the screening program, incidence of gastric cancer remains elevated.

The investigators propose to conduct a randomized controlled clinical trial in Korea to evaluate the efficacy of H. pylori eradication to prevent gastric cancer incidence in different population subgroups including age and baseline gastric pathology. This study will be conducted in the context of the National Cancer Screening Program and the Korean Central Cancer Registry.

The proposed study will be a collaborative investigation between the National Cancer Center, Korea and the International Agency for Research on Cancer of the World Health Organization.

Inclusion Criteria:

• Men and women aged 40-65 who are invited to participate in the National Cancer Screening Program and receive upper endoscopy
• Willingness to sign an informed consent form
• Good health, as determined by medical history and physical examination at enrollment

Exclusion Criteria:

• Personal history of gastric cancer
• Family history of gastric cancer in a first degree relative
• Diagnosis and active treatment for other organ cancer except carcinoma in situ within 5 years
• Current treatment for serious medical condition which could hinder participation (such as liver cirrhosis, renal failure, pulmonary dysfunction including COPD or asthma, or uncontrolled infection)
• Inadequate cardiovascular function including (a) New York Heart Association class III or IV heart disease, (b) unstable angina or myocardial infarction history, (c) history of significant ventricular arrhythmia requiring medication with antiarrhythmics, and (d) history of cerebrovascular accident
• Requirement for therapeutic anticoagulant therapy, aspirin
• Gastric resections due to benign disease
• H. pylori eradication therapy history
• Mental incompetence to understand and sign informed consent
• Alcoholism, drug abuse
• Serious chronic diseases according to the evaluation of the study physician
• Presence of a contraindication to the use of eradication treatment regimens
• Inability to provide an informed consent
• Pregnant or lactating women
• Treatment required due to peptic ulcer, gastric cancer or esophageal cancer identified during the endoscopic examination