Stratification of Gastric Cancer Risk by H. pylori Infection

Abstract

Infection by Helicobacter pylori (H. pylori) has been clearly shown to be strongly associated with the development of gastric cancer and is even considered a necessary condition for its development. In addition, it has been shown that among individuals with H. pylori infection, those who have advanced atrophy of the gastric mucosa are at high risk for gastric cancer. It is possible to evaluate the state of H. pylori infection by a serum antibody test for H. pylori and to evaluate the degree of gastric mucosal atrophy by the pepsinogen (PG) method. Furthermore, it is possible to stratify the risk for gastric cancer by using the ABC classification, which combines serum H. pylori antibody testing and the PG method. In this classification, a group of individuals who are H. pylori antibody (−) and PG method (−) (group A) is considered to be at low risk; a group with H. pylori antibody (+) and PG method (−) (group B) is considered to be at average risk; and groups with H. pylori antibody (+) and PG method (+) (group C) or H. pylori antibody (−) and PG method (+) (group D) are considered to be at high risk. The ABC classification is a simple, objective blood test, which is being widely used because it has the major advantage of providing consistent results regardless of the evaluating clinicians. The use of appropriate imaging studies based on the ABC stratification of gastric cancer risk would be an effective strategy toward elimination of gastric cancer.