title: Is there an association between ABO blood group and overall survival in patients with esophageal squamous cell carcinoma?
abstract: BACKGROUND
  The relationship between ABO blood group and clinical characteristics had been studied in several cancers. However, its role in esophageal cancer (EC) is unclear. The aim of this study was to determine whether ABO blood group is associated with overall survival in patients with esophageal squamous cell carcinoma (ESCC).
  
  
  METHODS
  From 2005 to 2008, a retrospective analysis of 496 consecutive patients with ESCC was conducted. The relationship between ABO blood group and clinicopathologic features of ESCC was analyzed. Prognostic factors for overall survival of ESCC were also analyzed.
  
  
  RESULTS
  The 5-year overall survival of ESCC patients with blood group A, B, AB and O were 47.8%, 44.1%, 43.2%, and 38.4%, respectively (P = 0.165). However, patients with blood group non-O have a better 5-year overall survival than patients with blood group O (45.7% vs. 38.4%; P = 0.043). Multivariate analyses showed ABO blood group (O vs. non-O; P = 0.034) is an independent prognostic factors.
  
  
  CONCLUSIONS
  ABO blood group is associated with overall survival in patients with ESCC. We concluded that patients with blood group O have a significantly worse overall survival than non-O blood groups.
authors.affiliation: Department of Thoracic Surgery, Zhejiang Cancer Hospital No. 38 Guangji Road, Banshan Bridge, Hangzhou 310022, China.
authors.forename: Xun
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Operating Theatre, Zhejiang Cancer Hospital No. 38 Guangji Road, Banshan Bridge, Hangzhou 310022, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Thoracic Surgery, Zhejiang Cancer Hospital No. 38 Guangji Road, Banshan Bridge, Hangzhou 310022, China.
authors.forename: Ji-Feng
authors.initials: JF
authors.lastname: Feng
keywords: ABO blood group; Esophageal cancer; esophagectomy; overall survival; prognostic factor; squamous cell carcinoma