Preoperative anaemia and perioperative red blood cell transfusion as prognostic factors for recurrence and mortality in colorectal cancer-a Swedish cohort study

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. 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. 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). 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.