Serum Helicobacter pylori CagA antibody as a biomarker for gastric cancer in east-Asian countries

Aims: In east-Asian countries, while almost all Helicobacter pylori strains possess the cytotokine-associated gene A (CagA) gene, serum CagA antibody is not detected in some infected subjects. We aimed to clarify the association between anti-CagA antibody and gastric cancer in east-Asian countries. Materials and methods: We performed a meta-analysis of case-control studies with age- and sex-matched controls, which provided raw data in east-Asian countries. Results: Ten studies with a total of 4325 patients were identified in the search. Some reports from Japan, Korea and China showed a positive association between the presence of anti-CagA antibody and gastric cancer; however, the results differed in their various backgrounds. The disparate findings appeared to result from the use of different methods or from variations in the antigens used to detect the anti-CagA antibody. CagA seropositivity was associated with an increased risk of developing gastric cancer. Conclusion: Anti-CagA antibody can be used as a biomarker for gastric cancer even in east-Asian countries.