Lymphocyte subsets, natural killer cytotoxicity, and perioperative blood transfusion for elective colorectal cancer surgery

Blood transfusions are associated with phenomena attributable to immune suppression. Since perioperative blood transfusion is associated with early cancer recurrence in patients with malignancies, we prospectively studied T-cell subsets and natural killer cytotoxicity in patients undergoing potentially curative surgery for colorectal cancer. Preoperative total peripheral lymphocyte number was significantly (P = 0.0191) depressed in patients who were subsequently transfused, but returned to normal by follow-up 1 to 3 months after surgery. Natural killer cytotoxicity declined significantly (P less than 0.05) at follow-up in patients who were not transfused. These results do not explain the association of blood transfusion with cancer recurrence observed in colorectal cancer patients. Blood transfusion in this study was followed by increased numbers of peripheral lymphocytes and higher natural killer cytotoxicity.