title: Perioperative blood transfusions reduce long-term survival following surgery for colorectal cancer.
abstract: OBJECTIVE
  The aim of the study contained herein was to investigate the association between blood transfusion and long-term outcome for patients treated for colorectal cancer, controlling for the effect of other prognostic factors. We also wanted to study whether blood storage time influenced the prognosis.
  
  
  METHODS
  Cox's proportional hazards regression analysis was used to analyze data from 336 patients who survived resection with curative intent. Median follow-up was 5.8 (2-16.8) years or until death.
  
  
  RESULTS
  Local recurrences and distant metastases were significantly more frequent when more than two units of blood had been transfused. In the multivariate Cox's analysis, with backward elimination of nonsignificant factors at the 10 percent level, the following risk factors were significantly related to death by colorectal cancer: tumor stage (T stage and N stage), perforation of tumor, age, and the need for a blood transfusion. Transfusions of more than two units of blood were independently and significantly associated with death from colorectal cancer (relative hazard, 2.7; 95 percent confidence intervals, 1.4-5.2). Time of blood storage had no effect on the prognoses. In patients dying from diseases unrelated to colorectal cancer, age and American Society of Anesthesiologists group were significantly related to death, whereas blood transfusion was not.
  
  
  CONCLUSIONS
  We found an independent and significant association between perioperative blood transfusion and poor prognosis in colorectal cancer patients. Blood storage time was not a prognostic factor.
authors.affiliation: Department of Surgery, Innherred Hospital, Levanger, Norway.
authors.forename: T H
authors.initials: TH
authors.lastname: Edna
authors.forename: T
authors.initials: T
authors.lastname: Bjerkeset
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001793:Blood Preservation / Q000009:adverse effects*; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015993:Life Tables; D008297:Male; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D012044:Regression Analysis; D016019:Survival Analysis; D013997:Time Factors; D065227:Transfusion Reaction