title: ABO genotype and the risk of gastric cancer, atrophic gastritis, and Helicobacter pylori infection.
abstract: BACKGROUND
  Although several studies have investigated the association between ABO blood type and risk of gastric cancer (GC), atrophic gastritis (AG), and Helicobacter pylori (HP) infection, no study has investigated these associations by using ABO genotype.
  
  
  METHODS
  We conducted a case-control study in 703 patients with GC and 1,465 noncancer patients. We also conducted a cross-sectional study by using 1,406 of these 1,465 controls, who were examined for pepsinogens and anti-HP IgG antibody levels in serum. ABO genotype was determined from single nucleotide polymorphisms in ABO gene. We used rs8176719 to mark the O allele, and rs8176746 and rs8176747 to mark the B allele. ORs and 95% CIs were calculated by a multivariate logistic model.
  
  
  RESULTS
  We observed significant associations between ABO genotype and GC, AG, and HP infection. ORs (95% CIs) of GC were 0.70 (0.50-0.99) for OO and 0.53 (0.36-0.77) for BO relative to AA genotype. An increased risk of GC was observed with addition of the A allele (P(trend) < 0.001), and a decreased risk with that of the B allele (P(trend) = 0.023). An OR of AG was 0.73 (95% CI, 0.53-0.99) for blood type B relative to blood type A, and an OR of HP infection was 0.39 (95% CI, 0.17-0.87) for BB relative to AA genotype.
  
  
  CONCLUSIONS
  This study identified a statistically significant association between ABO genotype and GC risk. In addition, ABO gene locus may influence AG prevalence and HP infection.
  
  
  CONCLUSIONS
  Further studies are necessary to confirm these findings.
authors.affiliation: Division of Epidemiology and Prevention, Aichi Cancer Center Research Institute, Chikusa-ku, Nagoya, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakao
authors.forename: Keitaro
authors.initials: K
authors.lastname: Matsuo
authors.forename: Hidemi
authors.initials: H
authors.lastname: Ito
authors.forename: Kohei
authors.initials: K
authors.lastname: Shitara
authors.forename: Satoyo
authors.initials: S
authors.lastname: Hosono
authors.forename: Miki
authors.initials: M
authors.lastname: Watanabe
authors.forename: Seiji
authors.initials: S
authors.lastname: Ito
authors.forename: Akira
authors.initials: A
authors.lastname: Sawaki
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Iida
authors.forename: Shigeki
authors.initials: S
authors.lastname: Sato
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yatabe
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamao
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Ueda
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tajima
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hamajima
authors.forename: Hideo
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005757:Gastritis, Atrophic / Q000097:blood* / Q000453:epidemiology / Q000235:genetics; D020022:Genetic Predisposition to Disease; D005838:Genotype; D016481:Helicobacter Infections / Q000097:blood* / Q000453:epidemiology / Q000235:genetics; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000097:blood* / Q000453:epidemiology / Q000235:genetics; D055815:Young Adult
chemical_list: D000017:ABO Blood-Group System