Abstract :
Epoetin (EPO; erythropoietin) treatment offers an attractive but costly alternative to red blood cell transfusion for managing anemia associated with cancer therapy. The goal of this paper is to review the findings of the 2001 Blue Cross/Blue Shield Association Technology Evaluation Center overview on EPO use in oncology, which served the foundation for the 2002 ASH/ASCO clinical guideline on this subject. The BC/BS review had two major aims: (1) to quantify the effects of EPO on the likelihood of transfusion and on quality of life in patients with cancer treatment-related anemia, and (2) to evaluate whether outcomes are superior when EPO treatment is initiated at higher hemoglobin thresholds. Two independent reviewers followed a prospective protocol for identifying relevant studies published between 1985 and 1998. Outcomes data were combined with the use of a random-effects meta-analysis model. Double-blind, randomized controlled trials that minimized patient exclusions were defined as higher quality for sensitivity analysis; randomized, but unblinded trials and trials with excessive exclusions were included in the meta-analysis, but were defined as lower quality. Twenty-two trials (n=1927) met inclusion criteria, and 12 (n=1390) could be combined for estimation of odds of transfusion. EPO decreased the percentage of patients transfused by 9–45% in adults with mean baseline hemoglobin concentrations of 10 g/dL or less (7 trials; n=1080), by 7–47% in those with hemoglobin concentrations greater than 10 g/dL, but less than 12 g/dL (7 trials; n=431), and by 7–39% in those with hemoglobin concentrations of 12 g/dL or higher (5 trials; n=308). In a sensitivity analysis, the combined odds ratio for transfusion in EPO-treated patients as compared with controls was 0.45 (95% confidence interval [CI]=0.33–0.62) in higher quality studies and 0.14 (95% CI=0.06–0.31) in lower quality studies. The number of treated patients needed to prevent one transfusion is 4.4 for all studies, 5.2 for higher quality studies, and 2.6 for lower quality studies. Only studies with mean baseline hemoglobin concentrations of 10 g/dL or less reported statistically significant effects of EPO treatment on quality of life; quality-of-life data were insufficient for meta-analysis. No studies addressed the effects of EPO on anemia-related symptoms. The review concluded that EPO reduced the odds of transfusion for cancer patients undergoing therapy. Evidence was insufficient to determine whether initiating EPO earlier spares more patients from transfusion or results in better quality of life than waiting until hemoglobin concentrations decline to nearly 10 g/dL. An update of this review, which includes information on quality of life, transfusion requirment, survival and tumor response, for first and second-generation epoetin products is ongoing.
