Chemotherapy-induced cognitive dysfunction: a clearer picture.

Chemotherapy-associated cognitive dysfunction occurs in a subset of patients treated with adjuvant chemotherapy. Recent data suggest that development of chemotherapy-related anemia predisposes patients to cognitive dysfunction. Endogenous erythropoietin (EPO) is well recognized for its central role in erythropoiesis, and recombinant human EPO (epoetin alfa) is established as a safe and effective treatment for chemotherapy-related anemia. Treatment with epoetin alfa also improved health-related quality of life in anemic cancer patients undergoing chemotherapy, and several controlled studies have documented increases in quality-of-life scores correlated with increases in hemoglobin. Erythropoietin also plays a role in neuroprotection, presumably by activation of antiapoptotic genes. Erythropoietin and its receptor are expressed in neural cells of the human brain, and their expression is upregulated after hypoxic or ischemic injury. In animal models, systemic administration of epoetin alfa protects against such neural injury. Ongoing and future studies will determine whether epoetin alfa can provide neuroprotection with respect to the development of cognitive dysfunction in patients undergoing adjuvant chemotherapy treatment for breast cancer.