Purpose: To determine the efficacy and safety of subcutaneous administration of recombinant human erythropoietin (r-HuEPO) at a dose of 200 units/kg/day to cancer patients undergoing radiotherapy.
Methods and materials: This is a randomized, open-labeled, Phase II study. Only patients receiving radiotherapy +/- chemotherapy are included. Eligibility is restricted to patients with lung cancer, carcinoma of the uterine cervix, prostatic adenocarcinoma, or adenocarcinoma of the breast. Patients in the control and treatment arms receive radiotherapy with similar policies, and their doses of radiotherapy and treatment volumes are determined by the site and stage of the disease. Patients in the "treatment arm" receive 200 units/kg/day of r-HuEPO, subcutaneously, five times a week with iron (Fe SO4, 325 mg. p.o., t.i.d.) supplements. Complete blood counts are obtained weekly. Quality of life is assessed weekly by the patients themselves by a few simple entries on an analog scale.
Results: Twenty-six patients have been entered in the study so far. Twelve patients were placed in the control arm and 14 in the treatment arm. Pre-randomization demographic and laboratory mean values in both arms were comparable, with none of 16 parameters compared reaching statistical significance. Our results can be summarized as follows: (a) Mean hemoglobin, hematocrit, and red blood cell values increased gradually in the treatment arm patients. Week-by-week comparison showed that mean values for these three parameters were significantly higher in the treatment arm than in the control arm. For example, the p values for the differences in hemoglobin mean values for weeks 1-6 were 0.015, 0.002, 0.003, 0.0002, 0.0006, and 0.007, respectively. Similar trends were observed for red blood cells and the hematocrit values. (b) No significant toxicity has been encountered. (c) No significant differences in the mean values of white blood cells and platelet counts were seen between the two arms. The values of these two parameters declined over the course of radiotherapy. (d) The mean weekly increase in hemoglobin levels in the treatment arm was 0.43 gm/dl.
Conclusion: (a) The safety and efficacy of r-HuEPO, with 200 units/kg/day of subcutaneous administration, have been confirmed in our study group. (b) However, the rate of increase in hemoglobin levels is not very rapid with the doses used. (c) Dose escalation studies are needed for determination of the feasibility of improving hemoglobin levels by about 1 gm/dl/week. (d) The question whether improvement in hemoglobin with r-HuEPO therapy can improve outcome by improving tumor oxygenation needs to be studied in carcinoma of the uterine cervix and squamous cell carcinoma of the head and neck.