title: Preoperative anaemia and perioperative red blood cell transfusion as prognostic factors for recurrence and mortality in colorectal cancer-a Swedish cohort study.
abstract: OBJECTIVE
  The hypothesis in this study was that anaemia prior to surgery and perioperative red blood cell transfusion increases the risk for recurrence and overall mortality in patients with stages I-III colorectal cancer after abdominal resection with curative intent.
  
  
  METHODS
  This is a Swedish single centre retrospective cohort study. Data on 496 consecutive radical abdominal resections stages I-III colorectal cancer performed at the Karolinska University Hospital 2007-2010 were extracted from the Swedish Colorectal Cancer Registry. Data were linked to local laboratory and transfusion databases to identify preoperative anaemia and perioperative transfusion. Disease recurrence was validated by scrutiny of patient records. A total of 496 stages I-III colorectal cancer patients were included in the analysis. Multivariate Cox regression analysis adjusted for tumour and patient characteristics were performed to assess risk for recurrence and overall mortality.
  
  
  RESULTS
  Anaemia prior to surgery was associated with increased risk for overall mortality (HR 2.1, 95% CI 1.4-3.2). There was no association between anaemia and risk for recurrence (HR 1.6, 95% CI 0.97-2.6). Transfusion was not associated with increased risk of recurrence (HR 0.7, 95% CI 0.4-1.3) or overall mortality (HR 1.04, 95% CI 0.7-1.6).
  
  
  CONCLUSIONS
  Anaemia prior to colorectal cancer surgery was associated with increased risk for overall mortality while a no increased risk was seen for recurrence. Previous findings indicating an association between blood transfusion and increased risk for recurrence could not be confirmed.
authors: Department of Clinical Science Intervention and Technology, Karolinska Institutet, Stockholm, Sweden. malin.morner@ki.se.|Functional Area of Emergency Medicine Huddinge, C1:63, Karolinska University Hospital, Huddinge, 141 86, Stockholm, Sweden. malin.morner@ki.se.
authors: Malin E M
authors: ME
authors: Mörner
authors: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors: Gustaf
authors: G
authors: Edgren
authors: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.|Center of Digestive Diseases, P9:03, Karolinska University Hospital, Solna, Sweden.
authors: Anna
authors: A
authors: Martling
authors: Department of Surgical and Perioperative Sciences, Umeå university, Umeå, Sweden.
authors: Ulf
authors: U
authors: Gunnarsson
authors: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.|Center of Digestive Diseases, P9:03, Karolinska University Hospital, Solna, Sweden.
authors: Monika
authors: M
authors: Egenvall
mesh_terms: D000368:Aged; D000740:Anemia / Q000150:complications*; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000601:surgery; D017707:Erythrocyte Transfusion; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D009367:Neoplasm Staging; D019990:Perioperative Care; D011300:Preoperative Care; D011379:Prognosis; D016016:Proportional Hazards Models; D012044:Regression Analysis; D013548:Sweden / Q000453:epidemiology
keywords: Anaemia; Colorectal cancer; Mortality; Recurrence; Survival; Transfusion