Do packed red blood cell transfusions really worsen oncologic outcomes in colon cancer?

Background. Data from small retrospective studies have argued that perioperative packed red blood cell transfusions may increase the risk of developing metastatic recurrence in cancer patients. This study tests this assumption in a large cohort spanning a decade of operatively treated colon cancer patients. Methods. All patients undergoing primary resection of a colon cancer at a tertiary care center between 2004-2014 (n=1,423) were included in a retrospective review of a prospectively maintained data repository. Survival and disease-free survival were compared and also adjusted in multivariable Cox regression standardized for follow-up, American Society of Anesthesiologists score, age, sex, postoperative chemotherapy, baseline staging, and tumor grade. Results. Of the 1,423 patients, 305 (21.4%) received a perioperative packed red blood cell transfusion during their index admission. During follow-up, overall mortality was greater in patients who received perioperative packed red blood cell (53.1 % vs 30.9%; P < .001); however, there were no appreciable differences in rates of long-term distant recurrence (in patients without baseline metastasis 11.1 % vs 13.9%; P=.25), or disease-specific mortality (21.3% vs 17.3 %; P=.104; without baseline metastasis: 8.6% vs 8.9%; P=.89). Similarly, multivariable Cox regression showed no statistical difference in recurrence (hazard ratio: 0.83, 95 % confidence interval, 0.83-1.26; P=.38) or disease-specific mortality (hazard ratio: 1.12, 95% confidence interval, 0.83-1.51; P=.47). Conclusion. Mortality rates were significantly greater in patients with perioperative packed red blood cell transfusions, a finding that is backed by a body of evidence that associates perioperative packed red blood cell transfusion with comorbidity and serious illness, but contrary to earlier evidence, findings in our cohort do not support a hypothesis that perioperative perioperative packed red blood cell transfusions have a detrimental effect on recurrence rates of operatively treated colon cancer patients.