Perioperative blood transfusion and colorectal cancer recurrence: a review.

Retrospective studies of the relationship between perioperative blood transfusion and colorectal cancer recurrence are reviewed. Perioperative blood transfusion was associated with preoperative anemia, operations for rectal carcinoma, presence of tumor in the right colon, prolonged procedures, and copious blood loss. Control for variables related to blood transfusion and potentially affecting disease recurrence--blood loss, duration of surgery, and magnitude of the procedure--was notably absent from the majority of studies. None of the negative studies had sufficient numbers of both transfused and untransfused patients to reject the hypothesis that blood transfusion is associated with cancer recurrence with statistical validity. No concensus emerged regarding the significance of blood transfusion for the patient with colorectal cancer, and no recommendations concerning the use of blood are justified on the basis of these studies.