Erythropoietin: the swinging pendulum.

Erythropoiesis stimulating agents (ESAs) have been used widely for anemic patients, especially those on dialysis and with cancer. However, reports have suggested shorter survival in erythropoietin (EPO)-treated cancer patients. The purpose of this review is to summarize and evaluate critically the current information about ESA treatment and its possible association with mortality in cancer patients. The pendulum that initially swung in the direction of widespread ESA treatment, and then in the direction of no treatment, is swinging back toward a stable position. This review also provides tools to decide how and when to use ESAs safely, according to accepted guidelines.