Usefulness of Serum Pepsinogen and Gastrin as the Predictive Biomarker of Atrophic Gastritis, Intestinal Metaplasia and Gastric Cancer in Korea

Inclusion Criteria: 1. over 19 years 2. the patients who have gastrointestinal discomfort or get esophagogastroduodenoscopy (EGD) for health check up 3. the patients who got the procedure, endoscopic submucosal resection (ESD) for early gastric cancer Exclusion Criteria: 1. gastrectomy history 2. advanced gastric cancer (impossible to get the gastrectomy) 3. Helicobacter eradication history 4. the patients who have chronic disease 5. cancer patients except gastric cancer within 6 months 6. who cannot perform this study according to research's decision 7. who have bleeding tendency (ex. taking antiplatelet agent, low platelet count or abnormal coagulation time)