Erythropoiesis-stimulating agents in oncology

Patients who have cancer, particularly those undergoing chemotherapy, frequently become anemic. Therapy with erythropoiesis-stimulating agents (ESAs) is associated with an increase in hemoglobin levels, a reduction in transfusion requirements, and, according to many clinical trialists and experienced clinicians, an improvement in functional status, productivity, and quality of life. Several randomized trials of ESAs in patients who have cancer have recently reported inferior outcomes in tumor progression or survival, raising appropriate concerns about the safety of ESAs in oncology. However, 3 important caveats to these reports exist. First, these clinical trials did not reflect the common use of ESAs in oncology practice (i.e., to treat, rather than prevent, anemia in patients undergoing chemotherapy). Second, the trials were seriously flawed and did not meet reasonable standards for cancer progression or survival trials. Third, during the same period, randomized trials were presented or published that showed no negative impact on tumor progression or survival; these trials have approximately the same shortcomings as trials that suggest a safety issue exists. The lack of definitive answers about the safety of ESAs for treating chemotherapy-related anemia has placed physicians, regulators, and most importantly patients in a difficult position that can only be addressed with additional data. This article reviews relevant preclinical and clinical available data to help improve understanding and guide decision making.