[The role of human recombinant erythropoietin in oncologic surgery]

Anemia is common in cancer patients, especially in those with more advanced stages of progressive tumor growth, the frequency varying on type of cancer, stage and chemotherapy or radiation therapy used. The pathophysiology is multifactorial. However the most common anemia is the anemia whose features are similar to those seen in other chronic diseases (anemia of chronic disease--ACD). The pathophysiological mechanisms are: a mild decrease in red blood cells survival, a decreased re-utilization of bone marrow iron stores and an inadequate erythropoietin response to the degree of anemia. When anemia cannot be corrected through the administration of hematinics and anemia is severe enough to significantly restrict physical activity and quality of life, blood transfusion is requested. It has been reported that the percentage of patients requiring transfusion ranges from 20 to 50%. The transfusion of allogeneic blood exposes the recipient to immunological and infectious risks. There is evidence that allogeneic blood transfusions can have immunologic consequences and some argue that these immune changes can adversely affect the prognosis in cancer patient. Although this is still controversial, until it can be shown that blood transfusion is not harmful in the long term to patients with cancer, it seems reasonable to avoid it whenever possible. Recently the availability of recombinant DNA technology permitted large scale production of recombinant human erythropoietin (rHuEPO). To date several clinical trials employed rHuEPO in anemic cancer patients with various solid tumors both on and off chemotherapy. All these studies have reported a significantly increase in Hct than placebo in more than 50% of the treated patients. The problem of correcting anemia and of blood transfusion is even more important when cancer patients become candidate to major surgery. In such situation, the transfusion of a consistent number of units is generally required to cover the surgical blood loss. The use of homologous blood in surgery can be substantially reduced by the introduction of autologous blood transfusion (ABT) programmes in association with rHuEPO. A number of experimental and clinical studies on the effects of rHuEPO on AB donation and on erythropoiesis in the peri-operative period have demonstrated that it resulted to be effective in stimulating erythropoiesis, with a consequent increase in the volume of red cells produced during the course of treatment and in the number of units predeposited. It was also effective in correcting anemia induced by collection of blood units. The efficacy of rHuEPO in increasing the volume of autologous blood the patient can predeposit before surgery has been demonstrated also in patients with ACD and cancer. No significant adverse effects of rHuEPO administration have been reported in any of the studies published to date. It can be concluded that rHuEPO therapy may be safe and effective in selected surgical patients, in stimulating erythropoiesis, in expanding the circulating RBCs mass, in increasing the volume of AB that can be collected pre-operatively and, consequently, in reducing the exposure to homologous blood. Therapy with rHuEPO may prove to be a useful addition to existing strategies of blood conservation to minimize exposure to HB.