Immunologic status of the cancer patient and the effects of blood transfusion on antitumor responses.

For patients undergoing potentially curative surgery for cancer, the perioperative period is when they appear to be most vulnerable. The antitumor immune response is subjected to a number of iatrogenic insults at this time, not the least of which is the surgery itself. Any improvements that can be made by a further understanding of the pathophysiology of the events in the perioperative period, and the therapeutic interventions to control them, would obviously benefit the patient. Over the past 10 years, the desire for such benefits has led to the intense investigation of "the blood transfusion effect" in cancer surgery, which this article reviews.