title: ABO blood group and risk of cancer: A register-based cohort study of 1.6 million blood donors.
abstract: The associations between ABO blood group and cancer risk have been studied repeatedly, but results have been variable. Consistent associations have only been reported for pancreatic and gastric cancers.
  
  
  
  We estimated associations between different ABO blood groups and site-specific cancer risk in a large cohort of healthy blood donors from Sweden and Denmark.
  
  
  
  A total of 1.6 million donors were followed over 27 million person-years (20 million in Sweden and 7 million in Denmark). We observed 119,584 cancer cases. Blood groups A, AB and B were associated either with increased or decreased risk of cancer at 13 anatomical sites (p≤0.05), compared to blood group O. Consistent with assessment using a false discovery rate approach, significant associations with ABO blood group were observed for cancer of the pancreas, breast, and upper gastrointestinal tract (mouth, salivary glands, pharynx, esophageal adenocarcinoma and stomach).
  
  
  
  Our study reconfirms the association between ABO blood group and cancer risk and exact underlying mechanisms involved needs further research.
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Senthil K
authors.initials: SK
authors.lastname: Vasan
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Jinseub
authors.initials: J
authors.lastname: Hwang
authors.affiliation: Department of Epidemiology Research, Statens Serum Institute, Copenhagen, Denmark.
authors.forename: Klaus
authors.initials: K
authors.lastname: Rostgaard
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Olof
authors.initials: O
authors.lastname: Nyrén
authors.affiliation: Department of Clinical Immunology, the Blood Bank, Rigshospitalet, University Hospital of Copenhagen, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Ullum
authors.affiliation: Department of Clinical Immunology, Næstved Hospital, Næstved, Denmark.
authors.forename: Ole B V
authors.initials: OBV
authors.lastname: Pedersen
authors.affiliation: Department of Clinical Immunology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Erikstrup
authors.affiliation: Department of Epidemiology Research, Statens Serum Institute, Copenhagen, Denmark; Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Mads
authors.initials: M
authors.lastname: Melbye
authors.affiliation: Department of Epidemiology Research, Statens Serum Institute, Copenhagen, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Hjalgrim
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Yudi
authors.initials: Y
authors.lastname: Pawitan
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; Hematology Centre, Karolinska University Hospital, Stockholm, Sweden. Electronic address: gustaf.edgren@ki.se.
authors.forename: Gustaf
authors.initials: G
authors.lastname: Edgren
mesh_terms: D000017:ABO Blood-Group System / Q000009:adverse effects / Q000235:genetics*; D000328:Adult; D001782:Blood Donors; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000209:etiology*; D012306:Risk; D055815:Young Adult
chemical_list: D000017:ABO Blood-Group System
keywords: ABO; Blood groups; Cancer; False-discovery rate