Effects of the combination of blood transfusion and postoperative infectious complications on prognosis after surgery for colorectal cancer

Background: The frequency of postoperative infectious complications is significantly increased in patients with colorectal cancer receiving perioperative blood transfusion. It is still debated, however, whether perioperative blood transfusion alters the incidence of disease recurrence or otherwise affects the prognosis. Methods: Patient risk variables, variables related to operation technique, blood transfusion and the development of infectious complications were recorded prospectively in 740 patients undergoing elective resection for primary colorectal cancer. Endpoints were overall survival (n=740) and time to diagnosis of recurrent disease in the subgroup of patients operated on with curative intention (n = 532). The patients were analysed in four groups divided with respect to administration or not of perioperative blood transfusion and development or non-development of postoperative infectious complications. Results: Overall, 19 per cent of 288 non-transfused and 31 per cent of 452 transfused patients developed postoperative infectious complications (P<0.001). The median observation period was 6.8 (range 5.4-7.9) years. In a multivariate analysis, risk of death was significantly increased among patients developing infection after transfusion (n=142) compared with patients receiving neither blood transfusion nor developing infection (n=234): hazard ratio 1.38 (95 per cent confidence interval (c.i.) 1.05-1.81). Overall survival of patients receiving blood transfusion without subsequent infection (n = 310) and patients developing infection without preceding transfusion (n = 54) was not significantly decreased. In an analysis of disease recurrence the combination of blood transfusion and subsequent development of infection (hazard ratio 1.79 (95 per cent c.i. 1.13-2.82)), localization of cancer in the rectum and Dukes classification were independent risk factors. Conclusion: Blood transfusion per se may not be a risk factor for poor prognosis after colorectal cancer surgery. However, the combination of perioperative blood transfusion and subsequent development of postoperative infectious complications may be associated with a poor prognosis.