Erythrocytosis associated with hepatocellular carcinoma.

I N A PREVIOUS STUDY, it was shown that erythrocytosis was present in 11.7 per cent of southern Chinese patients with hepatocellular carcinoma but that the mechanism of production remained obscure.’ Plasma erythropoiesis-stimulating factor ( ESF ), assayed on the fasted rat, was not increased in four subjects studied. Subsequent reports of the existence of erythrocytosis in hepatocellular carcinoma have appeared in the literature29 and the high incidence has been confirmed.9 Plasma ESF activity has been assayed in three instances,4’8’10 but in only one’#{176} was an increase found. Extracts of the tumor have been assayed on two occasions4’8 with negative results. Since it has been shown that measurement of red cell radioiron incorporation in polycythemic mice is a more sensitive and specific method for the bioassay of ESF,” further ESF assays by this method have been carried out in patients with hepatocellular carcinoma. The present communication reports the results of these studies.