The role of Helicobacter pylori in gastric cancer: A review

Gastric cancer is considered the third most common causes of mortality related with cancer in world. Gastric cancer has been classified as a class I carcinogen by World health organization. Investigation proposed that carcinogenic effect of Helicobacter infection can occurred through different mechanisms, one of these mechanism through indirect inflammatory on the gastric mucosa during Helicobacter pylori infection in addition to the direct  epigenetic effects of H. pylori on gastric cells. The development of gastric cancer depends on the combination of environmental and host depend factors in cooperation with Helicobacter pylori infection. There is a role for eradication of the H. pylori infections on the prevention the gastric lesions, which lead to atrophic gastritis. The aim of this review is to focus on the role of H. pylori infection in the development of gastric cancer, which helps physician in the best way to identify infected individual who is at high risk to affect with gastric cancer and achievement necessary investigation as well as treatment. Keywords: Helicobacter pylori; virulence; pathogenesis; gastric cancer; atrophic gastritis.