HELICOBACTER-PYLORI INFECTION AND GASTRIC-CANCER - A NESTED CASE-CONTROL STUDY IN A RURAL AREA OF JAPAN

We conducted a seroepidemiological nested case-control study to determ ine the association of gastric cancer with Helicobacter pylori infecti on and atrophic gastritis. A cohort of 2858 participants in an annual multiphasic health check-up were followed for eight years. Data for 45 gastric cancer cases and 225 sex-, age-, and address-matched control subjects were analyzed. Helicobacter pylori infection was determined b y IgG antibodies, and atrophic gastritis was diagnosed by both serum p epsinogen I level (less than or equal to 70 ng/ml) and the pepsinogen I/II ratio (less than or equal to 3.0). Univariate analysis showed tha t Helicobacter pylori and atrophic gastritis were significantly associ ated with gastric cancer. In a multivariate analysis, atrophic gastrit is was associated with significantly increased risk of cancer (odds ra tio, 3.38; 95% confidence interval, 1.54-7.42); however, Helicobacter pylori was not associated with cancer (odds ratio, 1.84; 95% confidenc e interval, 0.59-5.72). These results suggest that Helicobacter pylori infection alone is not directly associated with gastric carcinogenesi s but has an indirect relation to gastric cancer through the developme nt of atrophic gastritis.