Re-evaluation of laboratory predictors of response to current anemia treatment regimens of erythropoiesis stimulating agents in cancer patients

Anemia is a major cause of morbidity in cancer. Erythropoiesis stimulating agents (ESA) are a mainstay of treatment, although some patients lack response for unknown reasons. Recently, ESA dosing recommendations have changed and iron is increasingly used as an adjunct. Due to these changes, potential laboratory predictors of response were re-evaluated. This was a multi-center, observational study in cancer outpatients developing anemia under standard chemotherapy without absolute iron deficiency. For up to 12 weeks, laboratory data was collected while patients were treated with darbepoetin α (DA) either alone or along with intravenous iron. Baseline erythropoietin (Epo), changes in soluble transferrin receptor (sTfR) and in hemoglobin (Hb) early after treatment initiation were re-evaluated as response predictors, based on logistic regression models. Overall, 279 patients (mean age 66.1 years, 59.5% female) entered the study; 171 (61%) received at least one iron dose along with DA. Response and its predictability hardly increased through adjunct iron, although baseline ferritin