Peri-operative blood transfusion for resected colon cancer: Practice patterns and outcomes in a population-based study

Background & objectives: Literature suggests that peri-operative blood transfusion among patients with resected colon cancer may be associated with inferior long-term survival. The study objective was to characterize this association in our population. Methods: This is a retrospective cohort study using the population-based Ontario Cancer Registry (2002-2008). Pathology reports were obtained for a 25% random sample of all cases and constituted the study population. Log binomial regression was used to identify factors associated with transfusion. Cox proportional hazards model explored the association between transfusion and cancer specific survival (CSS) and overall survival (OS). Results: The study population included 7198 patients: 18% stage I, 36% stage II, 40% stage III, and 6% stage IV. Twenty-eight percent of patients were transfused. Factors independently associated with transfusion included advanced age (p < 0.001), female sex (p < 0.001), greater comorbidity (p < 0.001), more advanced disease (p < 0.001) and open surgical resection (p < 0.001). Transfusion was associated with inferior CSS (HR 1.51, 95% CI 1.38-1.65) and OS (HR 1.52, 95% CI 1.41-1.63), after adjusting for important confounders. Conclusions: Peri-operative transfusion rates among patients with colon cancer have decreased over time. Transfusion is associated with inferior long-term CSS and OS.