[Helicobacter pylori and gastric neoplasms: adenocarcinoma and lymphoma]

Helicobacter pylori is a risk factor for gastric carcinoma and an established carcinogenic bacterium. The relative risk to induce a gastric cancer is estimated to be 3 to 6 compared to that of individuals without H. pylori. Gastric atrophy and intestinal metaplasia in gastric mucosa are 2 well recognized precancerous lesions. Their occurrence and evolution are multifactorial depending on age at first infection, duration of infection and host's genetic characteristics. Prevention using H. pylori eradication is recommended only in individuals with high risk of cancer. Gastric lymphoma, although less frequent, may be due to H. pylori infection. Only in low grade lymphoma H. pylori eradication and periodic surveillance are recommended.