helicobacter pylori and gastric cancer: a state of the art review

gastric cancer ( gc ) is the fifth most common cancer in the world and has the third highest mortality rates, for both sexes. in 2012, just fewer than 1,000,000 new cases of gc were diagnosed, and 723,000 deaths were attributable to it. helicobacter pylori ( h. pylori ) plays a predominant role in the aetiology of gc and was characterised as a class i carcinogen by the world health organisation in 1994 . h. pylori is a microaerophilic gram-negative bacterium that colonises the gastric mucosa of 50% of the world’s population. the majority of infections are asymptomatic, hence screening and treatment programmes cannot be justified except for high-risk patients .   this review will assess the role of h. pylori in the pathogenesis of intestinal-type gastric carcinoma. the synergistic relationship of this bacterium with other host and environmental factors on the risk of subsequent neoplastic transformation will also be discussed