Diversity of gastric carcinogenesis.

Gastric cancer is still the second leading cause of cancer death worldwide, although the incidence of this disease has been gradually decreasing. The diversity of gastric cancer is well known. However, the mechanism underlying this diversity is still unknown. We have performed experimental and clinical studies on gastric carcinogenesis. These results suggest that the variety in the type and extent of inflammation in the stomach, and the different response to inflammation are responsible for the diversity in gastric carcinogenesis. This concept is supported by clinical and experimental evidence that eradication of Helicobacter pylori diminishes the incidence of gastric cancer and that PPAR gamma ligand, a modulator of inflammation and cell differentiation, prevents gastric carcinogenesis.