Supplemental Iron: A Key to Optimizing the Response of Cancer-Related Anemia to rHuEPO?
About 50% of cancer patients develop anemia; this incidence rises dramatically in patients with more advanced cancer or in those receiving chemotherapy or radiation therapy. Since the late 1980s, recombinant human erythropoietin (rHuEPO) has provided a safe and effective option for treating cancer-related anemia and fatigue. However, only about 50% of patients treated with rHuEPO adequately respond to therapy. In the chronic renal failure (CRF) population, true iron deficiency is the most common cause of an inadequate response to rHuEPO. Functional iron deficiency occurs when iron cannot be provided rapidly enough to meet the demands of rHuEPO-induced erythropoiesis, despite the presence of adequate bone marrow iron stores. It is hypothesized that functional iron deficiency can also occur in cancer patients receiving rHuEPO and may account for the lack of response in a proportion of the oncology population. Studies in CRF patients have shown that the administration of i.v. iron can correct functional iron deficiency more effectively than oral iron and may improve rHuEPO response. Therefore, it is important to monitor iron status and to address either true or functional iron deficiency prior to and during rHuEPO therapy to optimize the effect of rHuEPO in cancer patients. Studies are currently under way to determine the role of i.v. iron in treating cancer-related anemia.
Henry
DH
Allegheny University of the Health Sciences, Graduate Hospital, Philadelphia, Pennsylvania, 19146, USA. dhhenry@juno.com