title: Age-Specific Gastric Cancer Risk Indicated by the Combination of Helicobacter pylori Sero-Status and Serum Pepsinogen Levels.
abstract: 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 (sPGI low; OR = 2.6), to double (sPGI low/sPGI/II low; OR = 3.55, and Hp positive/sPGI low; OR = 5.0) and ultimately triple (Hp positive/PGI low/PGI/II low; OR = 10.48) positive states, in reference to the triple negatives. However, this pattern was not exhibited in the middle-aged subjects.
  
  
  CONCLUSIONS
  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 (Hp positive/sPGI low/sPGI/II low) 60 year-plus subjects, which was not evident in the middle-aged group.
authors.affiliation: HPGC Group, Dept. of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.|Research Center for Modeling in Health, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Sana
authors.initials: S
authors.lastname: Eybpoosh
authors.affiliation: HPGC Group, Dept. of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Yeganeh
authors.initials: Y
authors.lastname: Talebkhan
authors.affiliation: HPGC Group, Dept. of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Samaneh
authors.initials: S
authors.lastname: Saberi
authors.affiliation: HPGC Group, Dept. of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Esmaeili
authors.affiliation: HPGC Group, Dept. of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Akbar
authors.initials: A
authors.lastname: Oghalaie
authors.affiliation: HPGC Group, Dept. of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Ebrahimzadeh
authors.affiliation: HPGC Group, Dept. of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Toktam
authors.initials: T
authors.lastname: Karimi
authors.affiliation: Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Afshin
authors.initials: A
authors.lastname: Abdirad
authors.affiliation: Cancer Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Azin
authors.initials: A
authors.lastname: Nahvijou
authors.affiliation: Cancer Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Mohagheghi
authors.affiliation: Dept. of Gastroenterology, Amiralam Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Eshagh Hosseini
authors.affiliation: HPGC Group, Dept. of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Marjan
authors.initials: M
authors.lastname: Mohammadi
keywords: Age distribution; Biomarkers; Demography