Update on Erythropoiesis-Stimulating Agents and Clinical Trials in Oncology

Anemia commonly occurs among cancer patients receiving chemotherapy. In these patients, erythropoiesis-stimulating agents (ESAs) are effective in managing anemia but there is an increased risk for thrombovascular events. In more recent randomized clinical trials, there have been differing results regarding the impact of ESAs on overall survival and mortality. The balance between studies that show higher ESA-associated mortality and those that don't show ESA-associated mortality is examined in this review. This review discusses where we stand today on anemia management in cancer patients. Preliminary results from a recent independent patient data meta-analysis for on-study deaths and overall survival in patients receiving chemotherapy (the only oncology population for which ESA treatment is currently indicated) showed no statistically significant difference between the ESA and control groups (on-study deaths hazard ratio [HR], 1.10; 95% confidence interval [CI], 0.98-1.24; overall survival HR, 1.04; 95% CI, 0.97-1.11, compared with controls). Possible factors that could influence study results are discussed in this review. There are no convincing data to support ESA-induced tumor stimulation in patients. ESAs decrease RBC transfusion needs and sustain targeted hemoglobin levels, and this ESA response does not significantly impact overall survival or mortality when ESAs are used within guidelines and labeling. However, based on the currently available data and meta-analysis, the use of ESAs has to be carefully balanced against any possible risk for higher mortality. The Oncologist 2009; 14(suppl 1): 6-15