Increasingly, anemia is being recognized as a negative prognostic and predictive factor for patients undergoing chemotherapy, radiation therapy, or a combination of these treatment modalities. The results of clinical studies have shown correlations between anemia and shorter survival times in patients with a wide variety of solid tumors and hematologic malignancies, including lung, ovarian, breast, and head/neck cancers, non-Hodgkin's lymphoma, Hodgkin's disease, Waldenstrom's macroglobulinemia, and chronic lymphocytic leukemia. Also, anemia has been shown to predict treatment response in patients with ovarian, cervical, and urothelial cancers, mantle cell lymphoma, and chronic lymphocytic leukemia, as well as refractory/relapsed acute myelogenous leukemia. Based on the presumed causal relationship between anemia and poor patient outcome, several studies have examined the influence of epoetin alfa (a recombinant human erythropoietin) on outcomes in anemic patients undergoing cancer treatment. The results of these studies have been encouraging, with indications of greater locoregional tumor control and higher response rates in epoetin alfa-treated patients. Additionally, epoetin alfa therapy, by correcting anemia, has been shown to improve a patient's energy level, ability to perform daily activities, and overall quality of life (QOL). Such effects not only enhance a patient's general well-being, but may also increase their tolerance of, and willingness to undergo, full courses of their cancer therapy in a timely manner. These findings support the use of epoetin alfa to achieve gains in QOL and cancer treatment outcomes in anemic cancer patients and suggest that additional studies be conducted to further investigate the potential benefits of this agent in regard to improved outcomes.