To validated the OLGA and OLGIM staging system with serum pepsinogen to estimate gastric cancer risk according to Lauren's histologic classification in South Korea, where the incidence rate of GC is high. In addition, the investigators attempted to investigate the interaction among the several risk factors including OLGA or OLGIM staging system for the risk of GC to help establish surveillance strategy.
To validate OLGA and OLGIM staging system with serum pepsinogen for estimating GC risk according to Lauren's histologic classification in South Korea. Also attempted to estimate synergistic interaction among the several risk factors to help establish surveillance strategy.