Clinical trial experience using erythropoietin during radiation therapy

Oncologists have several reasons for trying to maintain or increase hemoglobin levels in their patients during therapy. Relief of the symptoms of anemia, including fatigue and dyspnea, are traditional, well-accepted indications. A newer rationale is to enhance the efficacy of radiation therapy and/or chemotherapy in controlling tumors. A laboratory animal study found that administration of recombinant human erythropoietin (rHuEPO) increased intratumoral median oxygen levels and diminished the proportion of measurements in the very low (< 3 mm Hg) range. Hemoglobin level is a strong independent prognostic factor for tumor control by radiation therapy. The hemoglobin level at the end of radiation therapy is a stronger prognostic factor than is the hemoglobin level at the start of therapy. Numerous clinical trials have utilized rHuEPO during radiation with or without concurrent chemotherapy. All 4 trials which enrolled patients with low hemoglobin levels (< 12 to 13.5 g/dl) found that rHuEPO significantly increased hemoglobin within 2 weeks and that hemoglobin levels continued to rise until the end of rHuEPO treatment. rHuEPO was efficacious in limiting the decrease in hemoglobin and use of packed red blood cell transfusion in the one reported trial in which it was used in patients with initially normal hemoglobin levels during intensive concurrent radiation and chemotherapy. One trial found a statistically significant improvement in complete pathologic response rate after neoadjuvant chemoradiotherapy with the use of rHuEPO. rHuEPO has a potentially large to play in the care of the cancer patient.