Helicobacter pylori and gastric cancer

Helicobacter pylori belongs to the most common bacterial infections worldwide; despite its decreasing prevalence during the past four decades (currently ~ 40–50%), it is more prevalent in developing countries compared to developed ones. Intensive research of chronic Helicobacter pylori infection clarified the pathogenesis of several gastric and extragastric diseases, including different cancers. This review pointed out the role of Helicobacter pylori in different gastric malignancies. Chronic Helicobacter pylori infection is an etiological factor in non-cardia gastric cancer and most cases of low-grade MALT lymphoma of the stomach. However, there is an inverse association of Helicobacter pylori infection with other gastric malignancies, like cardia gastric cancer or rare hereditary Gastric Adenocarcinoma and Proximal Polyposis of the Stomach syndrome (GAPPS). A crucial issue has not been definitely solved yet: whether early eradication of Helicobacter pylori could prevent sporadic gastric cancer in the future? There is moderate evidence that searching for and eradicating Helicobacter pylori reduces the incidence of gastric cancer and death from gastric cancer in healthy asymptomatic infected Asian individuals, although data cannot necessarily be extrapolated to European or US populations so far. Indication for the eradication of Helicobacter pylori must now be considered with caution, on an individual basis of personalized medicine.