Epidemiology of precancerous gastric lesions.

Research over the past several decades has revealed that the major subtype of gastric cancer (intestinal gastric cancer) is an end result of a multistage transformation of the gastric mucosa over many years and that this process is mainly determined by environmental factors. Epidemiologic studies on precancerous gastric lesions, including a large population-based study of the natural history and aetiology of precancerous gastric lesions conducted in Shandong, China, are reviewed.