Gastric cancer prognosis: strong correlation between incidence and survival.

Several studies previously reported better outcome in Asian Americans when compared with other ethnicities, and these findings are confirmed in recent reports. The explanation for this phenomenon is unknown. Even if molecular studies on Eastern and Western patients have been conducted, potential biological differences between patient cohorts are still unclear. We could suppose that two different biological entities of gastric cancer may exist: one with a low but uniform incidence throughout the world and higher biological aggressiveness, and a second form with wide variability in incidence and better prognosis. In low-risk areas, the higher relative proportion of the first form could explain the worse outcome with respect to geographic areas with higher incidence and proportion of the second form. These biological differences may be limited to noncardia tumors, and may be related to environmental factors acquired in youth.