Helicobacter pylori, pepsinogen, and risk for gastric adenocarcinoma.

The objective of this project was to determine the association of Helicobacter pylori infection and serum pepsinogen levels on subsequent risk for gastric adenocarcinoma. This nested case-control study was set in a large health maintenance organization. One hundred thirty-six cases of gastric adenocarcinoma and 136 matched controls without adenocarcinoma from a large cohort that had contributed serum in the 1960's were studied. The presence of IgG against H. pylori had previously been determined by enzyme-linked immunosorbent assay. Serum levels of pepsinogens I and II were ascertained by radioimmunoassay. In a sample of subjects, the presence of antiparietal cell antibodies was determined by immunofluorescent antibody assay (Nichols Laboratory). There were 98 cases of adenocarcinoma of the antrum, body, or fundus (distal cancers) and 30 of the cardia or gastroesophageal junction (proximal cancers). By univariate analysis, H. pylori infection [odds ratio (OR), 3.6; P < 0.001] and serum pepsinogen I < 50 ng/ml (OR = 2.9; P = 0.003) were both associated with development of distal cancer. In multivariate analysis, there was interaction between the two variables; H. pylori in the absence of low pepsinogen I was independently associated with cancer (OR, 2.4; P = 0.04) but low pepsinogen I in the absence of H. pylori infection was not associated with cancer (OR, 0.8; P > 0.5). In combination, however, H. pylori infection and a low pepsinogen I were associated with a marked increase in the risk of developing distal malignancy (OR, 10.0; P = 0.08).(ABSTRACT TRUNCATED AT 250 WORDS)