Helicobacter Pylori is the Cause of Human Gastric Cancer

Abstract

Background—Helicobacter pylori (HP) infection has been repeatedly reported to be associated with human gastric cancer (GC). However, Epstein Bar virus (EBV) has been found in gastric cancer tissues too. It is therefore not surprising that it proved difficult to establish a causal relationship between Helicobacter pylori and gastric cancer. A systematic review and meta-analysis of observational studies was performed to re-investigate the relationship between Helicobacter pylori and gastric cancer. Material and methods—The electronic database PubMed was searched for titles and abstracts of studies which investigated the relationship between HP and GC. Four eligible Japanese studies were included in this meta-analysis (196 incident gastric cancers among a total of 14792 individuals). The data available were analysed by new statistical methods. This study considers 5% as a reasonable cut-off for statistical significance. Results—The studies reviewed provided highly significant evidence that a HP infection is a necessary condition of GC. In everyday language, without a helicobacter pylori infection, no human gastric cancer (P Value < .004). In the same respect, the causal relationship between HP and GC was highly significant too. Conclusion—In a systematic review and meta-analysis, it was possible to establish a causal relationship between HP and GC. Helicobacter pylori is the cause of human gastric cancer. Keywords: Helicobacter pylori, human gastric cancer, cause effect relationshi