Population based Helicobacter pylori screening and eradication: advances versus side effects.

Gastric cancer is the fourth most common cancer in the world and second most common reason for cancer related death. Projections for the future predict that gastric cancer incidence will continue to rise. Risk factors for gastric cancer are Helicobacter pylori (H pylori) infection, host genetic factors and environmental factors. H pylori is a class I carcinogen and responsible for 60 % - 80 % of all gastric cancers of intestinal and diffuse type, as well as gastric MALT lymphoma. From animal and intervention studies we know that premalignant gastric lesions development and gastric cancer can be prevented with early H pylori eradication. In countries with gastric cancer incidence higher than 20 / 100 000 per year national screening for H pylori infection and eradication of all H pylori infections should be performed. Type of eradication therapy depends on local antimicrobial resistance rates. Quadruple bismuth or non- bismuth therapies can achive more than 90 % eradication rate. The success of eradication therapy must be controlled with noninvasive test. Patients with extensive preneoplastic changes (atrophy, intestinal metaplasia) should have endoscopic and histologic controls. Endoscopic screening should be performed in intervals according to the risk stratification by OLGA / OLGIM staging system or A-D staging system. In countries with high gastric cancer incidence national screening with serological tests for pepsinogen I (PGI), PGI/PGII ratio and H pylori antibodies can select patients at higher risk for gastric cancer.