title: Sex-specific differences in the association between ABO genotype and gastric cancer risk in a Korean population.
abstract: BACKGROUND
  Although previous studies have demonstrated an association between ABO blood group and the risk of gastric cancer (GC), only one study has identified these associations using the ABO genotype; however, that study did not evaluate sex differences in this association. The aim of the present study was to investigate whether there are sex-specific differences in the ABO genotype-associated risk of GC. In addition, we explored the association of the ABO genotype and the clinicopathologic characteristics of GC in a Korean population.
  
  
  METHODS
  We conducted a large-scale case-control study of 3245 GC patients (2204 males, 1041 females) and 1700 controls (821 males, 879 females). The ABO genotype was determined by multicolor real-time polymerase chain reaction (PCR) using displacing probes.
  
  
  RESULTS
  As compared with genotype OO, genotypes AA and AO in females, but not in males, were associated with a significantly increased risk of GC (odds ratio [OR] 1.56 and 95 % confidence interval [CI] 1.08-2.26 for AA; OR 1.57 and 95 % CI 1.21-2.03 for AO). In a subgroup analysis, blood group A had a significantly increased risk of diffuse-type GC (OR 2.00, 95 % CI 1.43-2.78), but not of intestinal-type (OR 1.31, 95 % CI 0.96-1.79) or mixed-type GC (OR 1.43, 95 % CI 0.92-2.24).
  
  
  CONCLUSIONS
  The ABO genotypes AA and AO were significantly associated with GC only in females and only for diffuse-type GC. These data suggest that the association between ABO blood group and GC risk may differ according to sex and histological type.
authors.affiliation: Department of Preventive Medicine, Chonnam National University Medical School, 5, Hak 1-dong, Dong-gu, Gwangju, Korea.
authors.forename: Hye-Rim
authors.initials: HR
authors.lastname: Song
authors.forename: Min-Ho
authors.initials: MH
authors.lastname: Shin
authors.forename: Hee Nam
authors.initials: HN
authors.lastname: Kim
authors.forename: Jin-Mei
authors.initials: JM
authors.lastname: Piao
authors.forename: Jin-Su
authors.initials: JS
authors.lastname: Choi
authors.forename: Jun-Eul
authors.initials: JE
authors.lastname: Hwang
authors.forename: Young-Kyu
authors.initials: YK
authors.lastname: Park
authors.forename: Dong-Wook
authors.initials: DW
authors.lastname: Ryang
authors.forename: Duck
authors.initials: D
authors.lastname: Cho
authors.forename: Sun-Seog
authors.initials: SS
authors.lastname: Kweon
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology
chemical_list: D000017:ABO Blood-Group System