The effect of perioperative blood transfusion on the outcome of cancer surgery

Homologous blood transfusion is associated with both beneficial and adverse clinical phenomena which are attributable to immune suppression. This association was first noted in dialysis patients: Transfusions suppress immune function and prolong survival of subsequently transplanted renal allografts. Transfusions are also beneficial for women suffering from spontaneous recurrent abortion: Transfusion with leukocyte-rich blood from their spouse is often followed by successful pregnancy. Blood transfusion has also been credited with prolonging the disease-free interval in immunologically-mediated diseases such as inflammatory bowel disease. However, not all the immunologic consequences of blood transfusion are beneficial to the recipient. Studies of patients undergoing elective and emergency surgery have observed an increased risk of infection following transfusion which is apparently reduced in elective procedures by the use of autologous blood. In cancer patients perioperative blood transfusion is associated with early recurrence and poor survival following surgery for a variety of malignancies. We will review the evidence linking transfusion to cancer recurrence focusing on colorectal cancer because more studies of colorectal cancer and blood transfusion have been published than all other malignancies combined.