Decreasing Incidence of Gastric Cancer and H. pylori Infection a 10- Year Study from an Asian Population

Worldwide, cancer of the stomach is the fourth most common cancer and is the second leading cause of cancer deaths. Gastric cancer is common in many regions of Asia and one of the many factors associated with it is the high prevalence of Helicobacter pylori [Hp] infection. Hp has been designated by the WHO as a class 1 (definite) carcinogen and the association between chronic Hp infection and the development of gastric cancer has been established by numerous publications. Up to 76-95% of gastric cancers are associated with Hp infection [1-3]. Among the many factors expressed by Hp, gastric carcinogenesis via the cag A pathway is the most studied. In individuals infected with CagA-positive strains, a meta-analysis of 16 case-control studies showed a further increase in the risk for gastric cancer by 1.64 fold [4] However, due to improved sanitation amidst better living conditions, heightened patients and physician awareness and widespread Hp eradication practices, a decreasing prevalence of Hp infection is observed even in previous high-prevalence regions. We have also noted that the number of patients with gastric cancer consulting our institution, a tertiary academic hospital, has diminished remarkably in the last several decades. Thus, we designed a study to determine the incidence of gastric cancer, as well as, Hp infection over a ten-year period as seen in our tertiary referral center and evaluated the relationship between Hp infection and gastric cancer.