age-specific gastric cancer risk indicated by the combination of helicobacter pylori sero-status and serum pepsinogen levels

background: serologic screening of gastric cancer (gc) by serum pepsinogens (spg) levels and helicobacter pylori (hp) sero-status, though highly informative, has provided heterogeneous results. here, we have evaluated the modifying effects of demographic factors on the risk impact of hp sero-status/spg levels in gastric cancer, with particular emphasis on age. methods: a cross-sectional study was carried out on 1341 individuals (gc = 578, healthy = 763), who were stratified into two age groups: 35-59 years (middle-aged, n = 830) and ≥ 60 years (60 years-plus, n = 511). demographic factors and serological states (hp sero-staus and spg levels) were recorded by subject interview and serum elisas, respectively. covariate-specific odds ratios were calculated by multivariable logistic regression. results: hp infection was consistently associated with increased spgi and spgii levels in the 60 year-plus, but not the middle-aged group. the joint examination of the variable states of the three serum biomarkers (hp serology, spgi, and spgi/ii ratio), in the 60 year-plus age group, demonstrated a stepwise escalation of risk from the single (spgilow or = 2.6), to double (spgilow/spgi/iilow or = 3.55, and hppositive/spgilow or=5.0) and ultimately triple (hppositive/pgilow/pgi/iilow or=10.48) positive states, in reference to the triple negatives. however, this pattern was not exhibited in the middle-aged subjects. conclusion: age was clearly identified as a modifying factor on the risk projection of the combined states of hp serology and spg levels in gastric cancer screening, reflected by the augmented (~10.5 fold) risk of gc in the triple positive (hppositive/spgilow/spgi/iilow) 60 year-plus subjects, which was not evident in the middle-aged group.