Helicobacter pylori infection,but not genetic polymorphism of CYP2E1, is highly prevalent in gastric cancer patients younger than 40 years

Background Gastric cancers in young adults are thought to be associated with risk factors that include Helicobacter pylori infection and genetic polymorphism. The objective of this study was to elucidate the roles of these risk factors in patients younger than 40 years by analyzing clinicopathological data and H. pylori infection, and using molecular epidemiologic techniques. Methods Clinicopathological features, the presence of H. pylori infection, endoscopic characteristics of gastritis, genetic polymorphism of P4502E1 (CYP2E1), and family history of cancer in patients with gastric cancer treated surgically at Nippon Medical School Hospital from 1991 to 2004 were analyzed, based on our medical database. Results Gastric cancer in those younger than 40 years was characterized by a predominance of female patients with poorly differentiated adenocarcinoma who had undergone total gastrectomy with extended lymphadenectomy. H. pylori infection had a higher prevalence in patients with gastric cancer than in patients with normal endoscopic results or chronic gastritis, especially in those younger than 40 years (odds ratio, 13.7). Atrophic gastritis, nodular gastritis, and rugal hyperplastic gastritis were observed by endoscopy as H. pylori-associated gastritis. No difference in the incidence of either CYP2E1 genetic polymorphism or a family history of cancer was observed among different age groups. Conclusion Gastric cancer in patients younger than 40 years is closely associated with H. pylori infection, but not with genetic characteristics. Eradication therapy for H. pylori and endoscopic examination of H. pylori-positive young adults may be anticipated to be adopted as a strategy for the prevention and/or early detection of cancer.