Serum erythropoietin concentrations in patients with hepatocellular carcinoma.

Erythrocytosis (polycythemia) is a well-described paraneoplastic phenomenon in patients with hepatocellular carcinoma, but its pathogenesis remains uncertain. Using a radioimmunoassay, we have measured serum erythropoietin concentrations in 65 southern African blacks with this tumor and 61 matched controls. Four patients had an increased hemoglobin concentration and packed cell volume, and the remainder had normal values. Twenty-three percent of the patients with hepatocellular carcinoma (15/65) were found to have raised serum erythropoietin concentrations, the values ranging up to 344 mu/ml. Only one of these patients had an increased hemoglobin concentration and packed cell volume. This apparent anomaly could be explained if the erythrocytosis that would normally result from high serum erythropoietin values had been counteracted by the inhibition of erythropoiesis which occurs in advanced malignant disease. Alternatively, the erythropoietin produced by the tumor might not always be biologically active. Three patients had increased hemoglobin values and packed cell volumes in the presence of normal serum erythropoietin concentrations. One of these patients was hypoxic as a result of multiple pulmonary metastases, and the others may also have been. There was no correlation between serum erythropoietin and alpha-fetoprotein concentrations in individual patients.