Adverse relationship between blood transfusions and survival after colectomy for colon cancer.

Random-donor blood transfusions are deliberately given before cadaver renal allografting to improve allograft survival. Since host modifications that improve the outcome of an allograft might be associated with a decreased ability of the host to control cancer growth, the relationship between blood transfusions and the outcome of 146 Dukes' stages A, B, and C colon cancers treated by resection during the years 1974 to 1979 was studied. It was found that 65 patients (45%) had been transfused and that at 5 years, overall survival was significantly better in the nontransfused patients compared to the transfused patients (0.68 and 0.51 5-year product limit survival fractions respectively; P = 0.03 for unadjusted log-rank comparison of entire survival curves). Relative risk of death due to cancer in transfused patients versus nontransfused patients was 2.3 (P = 0.05) when controlled for sex, age, stage, histologic differentiation, cancer location, and pre-resection hemoglobin level using Cox regression analysis. Thus, blood transfusion appears to be an additional important prognostic variable. The hypothesis suggested but not proven by these data that the outcome for some malignancies may be related to the immunomodulating effects of blood transfusions needs further study.