[Epidemiological study on the risk of gastric cancer in patients with duodenal ulcer]

Patients who were diagnosed to have duodenal ulcer (DU) or duodenal ulcer scar (DUS) by gastric mass screening with X-Ray examination from April 1970 to Dec. 1983 were followed up to Dec. 1983 by means of record linkage to the Osaka Cancer Registry, and incident patients of gastric cancer (GC) among the study subjects during the follow-up period were investigated almost completely. Standardized incidence rates (SIR) of GC for the groups categorized by diagnosis at the initial screening, i.e., DU or DUS group and normal group, were calculated by comparing the number of GC among the study groups with the expected number of GC. This expected number was obtained by multiplying the person-year of the study subjects with GC incidence rates for the whole population of Osaka prefecture according to sex and age group. SIR were calculated by sub-groups, i.e., male and female groups, under 5 year follow-up (from the initial screening to GC diagnosis) and 5 year follow-up or over groups, and direct X-Ray examination at the detection center and indirect X-Ray examination in the screening bus groups. The results were as follows. The SIR were 0.41 for the DU or DUS group and 0.74 for the normal group. The risk for the DU or DUS group was lower than that for the normal group (R.R. = 0.55, chi 2 = 3.56, 0.1 greater than p greater than 0.05). In all subgroups, the risk of GC for each DU or DUS group was lower than that for the normal group.(ABSTRACT TRUNCATED AT 250 WORDS)