Anemia is a common complication among cancer patients. Not only can it cause physical symptoms and diminish a patient's quality of life, but anemia may also result in a poorer response to radiotherapy or chemotherapy due to increased tumor hypoxia. Researchers have hypothesized that reducing the anemia with the use of recombinant human erythropoietin may be able to improve tumor response and improve survival, but trials testing this hypothesis have had conflicting results.
To determine the association between erythropoietin treatment and hematologic response, blood transfusions, adverse events, and overall survival, Andreas Engert, M.D., of the University of Cologne in Germany, and colleagues conducted a meta-analysis of 27 randomized, controlled trials published between 1993 and May 2002. The trials had compared erythropoietin treatment versus no treatment in a total of 3,287 adult cancer patients.
The likelihood of needing a blood transfusion was lower in patients who received erythropoietin treatment than in those who did not. Erythropoietin-treated patients with very low baseline hemoglobin levels were more likely to have a hematologic response than untreated patients. The risk for thromboembolic events was similar in both groups.
The researchers also found suggestive but inconclusive evidence that erythropoietin may improve overall survival. However, this contrasts with the results of two recently published randomized controlled trials--which were not included in this analysis because they were published after the cutoff point for inclusion in the systematic review--in which patients treated with erythropoietin had worse survival than untreated patients.
"In view of the inconclusive evidence presently available, our results suggest that erythropoietin should not be used to increase overall survival outside clinical trials," the authors write. "Erythropoietin may be used routinely outside of clinical trials to increase hemoglobin levels and to reduce the need for transfusion in patients with falling hemoglobin levels approaching 10 g/dL. Adverse events such as thromboembolic complications and hypertension should be monitored."
Contact: Andreas Engert, University of Cologne, a.engert@uni-koeln.de
Citation: Bohlius J, Langensiepen S, Schwarzer G, Seidenfeld J, Piper M, Bennett C, et al. Recombinant Human Erythropoietin and Overall Survival in Cancer Patients: Results of a Comprehensive Meta-analysis. J Natl Cancer Inst 2005;97:489–98.
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JNCI Journal of the National Cancer Institute