Gastric screening prospects.

The incidence of gastric cancer is rapidly declining in the Western world, but it remains high in the Third World and in Japan. Systematic screening for gastric cancer has been undertaken in Japan, where barium X-ray is used in people over the age of 40. Evaluation data suggest a benefit in reduced mortality, but biases cannot be ruled out. A similar screening programme has been started in Venezuela. Currently, stomach cancer screening programmes cannot be recommended as public health policy, except in high-risk areas where they have already started. The Correa model of gastric carcinogenesis states that environmental influences cause a normal gastric mucosa to undergo successive stepwise changes, through superficial gastritis, atrophic gastritis, intestinal metaplasia, dysplasia, carcinoma and, finally, invasion. Incriminated environmental influences include irritant, antibodies, gastrectomy, nutritional deficits, intake of nitrogen compounds and Helicobacter pylori. These bacteria cause a chronic superficial gastritis, which may develop into atrophic gastritis. H. pylori is less frequently found in advancing preneoplastic lesions, and seldomly in gastric carcinoma tissue (it may, however, be identified more readily in the surrounding non-cancerous tissue). Several lines of evidence suggest that H. pylori may play an important role in human gastric carcinogenesis. We found that in some patients with H. pylori infection and without preneoplastic lesions, the gastric cell turnover was increased; this was correlated with the intensity of the inflammatory changes.(ABSTRACT TRUNCATED AT 250 WORDS)