Recurrence of colorectal cancer and perioperative blood transfusion. Is blood storage time important?

In a prospective study of 35 patients undergoing surgery for colorectal cancer, the mitogenic activity of plasma was measured using 3T3 Swiss fibroblasts as target cells. Transfused patients exhibited a 100 percent increase in mitogenic activity over preoperative values compared with no significant change in nontransfused patients. Samples were taken from blood during 28 days of storage following donation, and mitogenic activity measured. The mitogenic activity increased with storage time, the principal changes occurring from the end of the second week. The increased mitogenic activity in patients following transfusion and in stored blood may be a factor in the mediation of the deleterious effect of transfusion on recurrence in colorectal cancer and perhaps "fresh" blood, if required, should be used.