title: ABO and Rh blood groups and risk of colorectal adenocarcinoma.
abstract: BACKGROUND
  Previous studies have observed an association between ABO blood group and risk for certain gastrointestinal malignancies, including pancreatic and gastric cancer. However, it is unclear whether there is such an association with colorectal cancer (CRC). In this study, possible relationships between ABO blood groups and Rh factor and KRAS status in patients with CRC were investigated.
  
  
  METHODS
  In 1,620 patients with CRC, blood group and Rh factor were examined and compared with the control group of 3,022,883 healthy volunteer blood donors of the Turkish Red Crescent between 2004 and 2011. The relationship of blood groups with wild type K-ras status was also evaluated.
  
  
  RESULTS
  Overall distributions of ABO blood groups as well as Rh factor were comparable between patients (45% A, 7.2% AB, 16.4% B, 31.4% O, and 87.2% Rh+) and controls (42.2% A, 7.6% AB, 16.3% B, 33.9% O, and 87.7% Rh+) (p=0.099). However, there were statistically significant difference between patients and controls with respect to O vs. non O blood group (p=0.033) and marginally significant difference for A vs. non-A blood group (p=0.052). Among patients, the median age was 62 (range 17-97), 58.1% were male. There were no statistically significant differences respect to sex and K-ras status.
  
  
  CONCLUSIONS
  In present study, the ABO/Rh blood groups were statistically significantly associated with the risk of CRC. There were no relationship between K-ras status and ABO blood group and Rh factor. However further studies with larger numbers of patients are needed to establish the role of blood groups and to define the mechanisms by which ABO blood type affect CRC.
authors: Department of Medical Oncology, Ankara University Faculty of Medicine, Turkey. yukselurun@gmail.com
authors: Yuksel
authors: Y
authors: Urun
authors: Nuriye Yildirim
authors: NY
authors: Ozdemir
authors: Gungor
authors: G
authors: Utkan
authors: Hakan
authors: H
authors: Akbulut
authors: Berna
authors: B
authors: Savas
authors: Berna
authors: B
authors: Oksuzoglu
authors: Derya Gokmen
authors: DG
authors: Oztuna
authors: Izzet
authors: I
authors: Dogan
authors: Bulent
authors: B
authors: Yalcin
authors: Filiz Cay
authors: FC
authors: Senler
authors: Handan
authors: H
authors: Onur
authors: Ahmet
authors: A
authors: Demirkazik
authors: Nurullah
authors: N
authors: Zengin
authors: Fikri
authors: F
authors: Icli
mesh_terms: D000017:ABO Blood-Group System / Q000097:blood; D000230:Adenocarcinoma / Q000097:blood; D015179:Colorectal Neoplasms; D006801:Humans; D012204:Rh-Hr Blood-Group System / Q000097:blood; D012306:Risk
chemical_list: D000017:ABO Blood-Group System; D012204:Rh-Hr Blood-Group System