title: Prevalence of subjects at a high or very high risk of gastric cancer in Japan.
abstract: OBJECTIVE
  The presence of Helicobacter pylori (H. pylori) infection represents a high-risk state of gastric cancer, but the risk is even higher in gastric atrophy. H. pylori stool antigen (HpSA) and serum pepsinogen (PG) tests are useful tools for screening present infection and gastric atrophy, respectively. To determine the prevalence of subjects at a high risk (HpSA+ or PG+) or very high risk (PG+) of gastric cancer in Japan, we applied the two tests to a general population.
  
  
  METHODS
  The subjects included 311 volunteers. We used Meridian HpSA ELISA for the HpSA test and Pepsinogen RIA Beads for the PG test. PG I at </=70 microg/L and I/II ratio of </=3.0 were used as cutoffs for PG-test positivity.
  
  
  RESULTS
  Positivity rates in HpSA and PG tests significantly increased with age in those younger than 60 years and in all age groups, respectively. The proportions of HpSA-/PG- and HpSA+/PG+ sujects decreased and increased with age, respectively. A small proportion of HpSA-/PG+ subjects were older than 40 years. The prevalence of subjects who were either HpSA+ or PG+ increased with age (>50% of those older than 40 years). Half of the subjects older than 60 years were PG+.
  
  
  CONCLUSIONS
  In Japan, more than 50% of general population aged >/=40 years is at a high risk of gastric cancer, and half of the population aged >/=60 years is at a very high risk.
authors.affiliation: Department of Healthcare, Social Insurance Shiga Hospital, Otsu, Japan.
authors.forename: Miyoko
authors.initials: M
authors.lastname: Yamaoka
authors.forename: Shigemi
authors.initials: S
authors.lastname: Nakajima