Changes in serum erythropoietin levels during chemotherapy for lung cancer.

Serial serum erythropoietin (EPO) levels were measured in 12 adult lung cancer patients during cancer chemotherapy. In major cases, EPO levels increased significantly after chemotherapy while the hemoglobin (Hb) remained at initial levels. EPO fell gradually or rapidly to initial levels after a peak, although the patients were anemic. The increase of EPO levels was linearly related to the decrease in Hb (y = 17.48x + 1.003). The mechanism of the rapid increase of EPO is not simply explained by anemia, but might be related to new synthesis, corresponding to depressed bone marrow.