Anemia in Cancer Patients
Anemia can compromise the delivery of sufficient amounts of oxygen to all cells, including tumor cells. This hypoxic condition can worsen the results of radiotherapy and chemotherapy, because low tissue oxygenation is associated with a reduced sensitivity of tumors to radiation and some forms of chemotherapy, contributing to the progression of cancer and reduction in survival.[4,5] Furthermore, there is abundant evidence suggesting that hemoglobin levels of less than 12 g/dl result in worse QOL and functional status for cancer patients when compared with higher levels. Present treatment options for anemia include blood transfusions, iron supplementation when there is iron deficiency or erythropoiesis-stimulating agents (ESAs), such as recombinant human erythropoietin (EPO) and darbepoetin-α. Given the impact of anemia on the survival of cancer patients, the management of anemia has been explored in several clinical trials to date.
The epidemiology of anemia in cancer patients was evaluated in at least two large studies. The European Cancer Anemia Survey (ECAS), conducted between 2001 and 2002, was a large, prospective study of 15,367 patients with cancer at any stage and who were undergoing treatment of any type. Approximately 40% of patients had hemoglobin levels lower than 12 g/dl, and 75% of patients undergoing chemotherapy developed anemia within 6 months. Factors independently associated with the development of anemia were the baseline level of hemoglobin, the site of the primary tumor, the use of platinum-containing regimens, female gender, advanced age and low performance status. An interesting finding from the ECAS study was that only 40% of patients received treatment for anemia: 17.4% of patients were treated with EPO, 15% received blood transfusion and only 6.5% were treated with iron. The Anemia of Cancer Therapy (ACT) study was a retrospective, observational evaluation of 2192 cancer patients with hemoglobin levels of less than 11 g/dl, conducted between 2005 and 2007. This study evaluated the patterns of treatment for anemia and the effectiveness of such treatment. The ACT study found a greater percentage of patients treated for anemia (68.3%) than the ECAS study: ESAs were used in 62.2% of patients, blood transfusions were performed in 19.4% of patients and 32.8% received iron supplementation. In the ACT study, the use of ESAs was able to raise hemoglobin levels by an average of 1.34 g/dl. The differences between these two studies in the proportion of patients treated for anemia, as well as in the use of therapeutic modalities, suggest a growing recognition of the importance of management of anemia in cancer patients.
Future Oncol. 2011;7(4):507-517. © 2011 Future Medicine Ltd.
Cite this: Management of Anemia in Cancer Patients - Medscape - Apr 01, 2011.