The Haematological Complications of Polycythaemia Vera and Treatment with Radioactive Phosphorus

Abstract

1. Haematological complications developed in 18 of a series of 169 patients with polycythaemia vera, seen over a 16-year period and treated with 32P. The complications are considered under three headings: marrow depression, myelosclerosis, and granulocytic leukaemia. 2. Two patients developed pancytopenia. Attention is drawn to the rarity of this complication, and differences from other forms of marrow hypoplasia are discussed. 3. Myelosclerosis occurred much more frequently than leukaemia in this series (12 cases of myelosclerosis as compared with four of leukaemia). The difficulties which may be encountered in distinguishing between the two conditions are emphasised. The clinical and haematological features in the patients who developed myelosclerosis and leukaemia are compared with the findings in the patients who did not develop these complications. 4. The difficulty of assessing the role of 32P in causing or increasing the incidence of these complications is discussed. Leukaemia and myelosclerosis occur in polycythaemic patients not treated by ionising radiation. It is therefore possible that an increased incidence may merely be a result of the prolongation of life produced by treatment with 32P. It is perhaps more likely, however, that radioactive phosphorus both prolongs life and also increases the frequency of leukaemia. 5. It is concluded that the relationship between the development of myelosclerosis and leukaemia and treatment with 32P could be clarified only by a planned and statistically valid investigation. A plea is made for co-operative efforts to organise such an investigation.