Changes in levels of serum erythropoietin, serum iron and unsaturated iron binding capacity during chemotherapy for lung cancer

BACKGROUND: The serum erythropoietin level increases markedly duringchemotherapy for leukemia. A number of hypotheses have been built for themechanism, none of them satisfactory. Difficulty in evaluating bone marrowactivity hampers the elucidation. Therefore, we focused on patients who hadnon-hematological cancer and no evidence of bone marrow suppression.METHODS: Twelve patients, who had lung cancer (four with small cell cancerand eight with non-small cell cancer) and who had not undergone anychemotherapy, were studied. During chemotherapy, we measured serumerythropoietin, serum iron, unsaturated iron binding capacity andhemoglobin concentration in these patients. RESULTS: The serumerythropoietin level before chemotherapy (10.8 +/- 7.4 mU/ml) was withinthe normal range but the peak values after the first treatment (73.4 +/-90.4 mU/ml) increased in all patients. In the patients with small cellcancer, a transient but marked increase in erythropoietin value (204.6 +/-167.3 mU/ml) was observed after each session of chemotherapy whilehemoglobin concentration decreased gradually. Throughout treatments,elevation of the serum iron concentration and concomitant reduction ofunsaturated iron binding capacity were observed after each session ofchemotherapy. They regained their original values whilst the serumerythropoietin level decreased after each chemotherapy session wascompleted. CONCLUSIONS: It is suggested that the suppression of erythroidmarrow by chemotherapeutic agents causes the changes in serumerythropoietin level during chemotherapy in patients with lung cancer.