Anemia in cancer patients: significance, epidemiology, and current therapy

Anemia in cancer patients is associated with a decline in energy levels, activity levels, and quality of life, and these variables improve when hemoglobin levels rise. Importantly, the impact of improved hemoglobin levels on response to chemotherapy, radiation therapy, and survival time is under study. This line of research follows favorable preliminary data in clinical studies suggesting improved treatment outcomes with reversal of anemia. It is estimated that there are 10 million people in the United States with cancer. Of the 1.3 million cancer patients who are anemic with hemoglobin levels less than 12 g/dL, about 800,000 are receiving chemotherapy and 500,000 are not. The predominant treatable cause of anemia in these patients is a relative lack of erythropoietin; overall, only 20% of anemic cancer patients receive a trial of erythropoietic therapy. About one-fourth (26%) of patients whose hemoglobin is less than 12 g/dL and who are receiving chemotherapy for cancer are currently receiving erythropoietic therapy. A review of the patients in our oncology practice revealed that 37% were anemic (hemoglobin < 12 g/dL) prior to chemotherapy, and an additional 41% became anemic during chemotherapy. Overall, 63% of our cancer patients on chemotherapy received erythropoietin; 6% of these patients received red cell transfusions. Only 7% of our patients had a hemoglobin level < 10 g/dL before chemotherapy; overall, 80% of our patients maintained hemoglobin levels > or = 10 g/dL at all times. Barriers to the use of erythropoietic agents include cost and reimbursement issues, inconvenience of frequent injections, limitations in efficacy, and indication restrictions. An understanding of the importance of anemia and newer agents requiring less frequent dosing, such as darbepoetin alfa (Aranesp), may help physicians and patients overcome some of these barriers.