Dissecting causal components in gastric carcinogenesis

Gastric cancer accounts for about 10% of all cancers worldwide, being the fourth most common cancer and the second most frequent cause of cancer death (Globocan, 2008). Incidence and mortality are high in various countries including Japan, China, Russia and most central and eastern European countries, where the prevalence of Helicobacter pylori (H. pylori) is relatively high compared with western Europe and the USA (60–90 vs. 30–40% of the population). There has been a steady decrease in the incidence of gastric cancer in many western countries, particularly for cancers located distal to the cardia and for the intestinal histotype. Besides the decrease in the prevalence of H. pylori, this decrease has been related to food refrigeration, a reduced intake of preserved foods and salt and a richer and more varied diet, including a higher intake of fruit and vegetable