title: ABO blood group and risk of epithelial ovarian cancer within the Ovarian Cancer Association Consortium.
abstract: OBJECTIVE
  Previous studies have examined the association between ABO blood group and ovarian cancer risk, with inconclusive results.
  
  
  METHODS
  In eight studies participating in the Ovarian Cancer Association Consortium, we determined ABO blood groups and diplotypes by genotyping 3 SNPs in the ABO locus. Odds ratios and 95 % confidence intervals were calculated in each study using logistic regression; individual study results were combined using random effects meta-analysis.
  
  
  RESULTS
  Compared to blood group O, the A blood group was associated with a modestly increased ovarian cancer risk: (OR: 1.09; 95 % CI: 1.01-1.18; p = 0.03). In diplotype analysis, the AO, but not the AA diplotype, was associated with increased risk (AO: OR: 1.11; 95 % CI: 1.01-1.22; p = 0.03; AA: OR: 1.03; 95 % CI: 0.87-1.21; p = 0.76). Neither AB nor the B blood groups were associated with risk. Results were similar across ovarian cancer histologic subtypes.
  
  
  CONCLUSIONS
  Consistent with most previous reports, the A blood type was associated modestly with increased ovarian cancer risk in this large analysis of multiple studies of ovarian cancer. Future studies investigating potential biologic mechanisms are warranted.
authors.affiliation: Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 181 Longwood Ave, 3rd Floor, Boston, MA 02115, USA. nhlip@channing.harvard.edu
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Poole
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Gates
authors.forename: Brigit A
authors.initials: BA
authors.lastname: High
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Chanock
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Cramer
authors.forename: Julie M
authors.initials: JM
authors.lastname: Cunningham
authors.forename: Brooke L
authors.initials: BL
authors.lastname: Fridley
authors.forename: Simon A
authors.initials: SA
authors.lastname: Gayther
authors.forename: Ellen L
authors.initials: EL
authors.lastname: Goode
authors.forename: Edwin S
authors.initials: ES
authors.lastname: Iversen
authors.forename: Jolanta
authors.initials: J
authors.lastname: Lissowska
authors.forename: Rachel T
authors.initials: RT
authors.lastname: Palmieri Weber
authors.forename: Paul D P
authors.initials: PD
authors.lastname: Pharoah
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Phelan
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Ramus
authors.forename: Joellen M
authors.initials: JM
authors.lastname: Schildkraut
authors.forename: Rebecca
authors.initials: R
authors.lastname: Sutphen
authors.forename: Ya-Yu
authors.initials: YY
authors.lastname: Tsai
authors.forename: Jonathan
authors.initials: J
authors.lastname: Tyrer
authors.forename: Robert A
authors.initials: RA
authors.lastname: Vierkant
authors.forename: Nicolas
authors.initials: N
authors.lastname: Wentzensen
authors.forename: Hannah P
authors.initials: HP
authors.lastname: Yang
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Terry
authors.forename: Shelley S
authors.initials: SS
authors.lastname: Tworoger
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000077216:Carcinoma, Ovarian Epithelial; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D009375:Neoplasms, Glandular and Epithelial / Q000097:blood* / Q000235:genetics; D010051:Ovarian Neoplasms / Q000097:blood* / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D044465:White People
chemical_list: D000017:ABO Blood-Group System