The relationship between
Helicobacter pyloriinfection and the risk of gastric cancer has been well established in the last decade. Four metaanalyses have found that the infection increases the risk of noncardia gastric cancer by 2- to 6-fold compared with noninfected control populations. However, the role of cagAstrains of H pyloriin relation to gastric cancer has not been evaluated systematically. We undertook a meta-analysis of epidemiological studies examining the relationship between infection with cagA-positive strains of H pyloriand the risk of gastric cancer, and found that patients who are seropositive for cagAstrains of H pyloriare at an increased risk for developing noncardia gastric cancer compared with those with H pyloriinfection alone. Therefore, searching for cagA-positive strains of H pylorimay help identify populations at a greater risk for developing gastric cancer.