Helicobacter pylori: gastric cancer and extragastric malignancies - clinical aspects

Abstract

The best opportunity to reduce gastric cancer (GC)-related mortality remains prevention. Mass eradication of Helicobacter pylori infection in a Taiwanese population >30 years of age reduced GC incidence with an effectiveness of 25% (rate ratio 0.753, 95% CI 0.372-1.524). In the Shandong intervention trial conducted on a Chinese population aged 35-64 years, cancer incidence was reduced by 39% in subjects who received H. pylori treatment compared with the placebo group after 14.7 years of follow-up (absolute risk 3.0 vs 4.6%; odds ratio 0.61, 95% CI 0.38-0.96; p = .03). A high incidence of severe gastric atrophic changes and noninvasive gastric neoplasia has been reported in a Portuguese case-control study on first-degree relatives of patients with early-onset gastric carcinoma (i.e., diagnosed before 45 years), which emphasizes again the importance of GC screening in this population. For patients with advanced GC, new targeted therapies to improve survival are under scrutiny. Trastuzumab resistance may be present from early on, or develop during trastuzumab therapy in patients with GC, and an overexpression of the HER2/neu protein. New molecules to overcome trastuzumab resistance are also being evaluated. The association between H. pylori-induced gastritis and an increased risk of developing colonic neoplasms has been confirmed in a recent study, but the causality for this intriguing association has still to be clarified.

Keywords: advanced gastric cancer; colon cancer; extragastric malignancies; screening; treatment.