Targeting Helicobacter pylori in gastric carcinogenesis.

Gastric infection by Helicobacter pylori is an important risk factor for the development of gastric cancer. Recent research has identified both bacterial and host factors related to increased gastric cancer risk, including virulence-associated genes located in the cytotoxin-associated gene pathogenicity island and the vacuolating toxin A exotoxin, as well as polymorphisms in key cytokines and cytokine receptors that mediate the host's gastric inflammatory response. Early randomized trials indicate that eradicating H. pylori with antibiotics may prevent gastric cancer, although the effects so far have been modest, and are probably confined to individuals who had not developed preneoplastic lesions at the time of eradication. Targeting H. pylori to prevent gastric cancer may be best achieved through vaccination, better understanding of the molecular pathogenesis of H. pylori-associated carcinogenesis and additional chemopreventive strategies.