[Fate of polycythemia vera treated by radioactive phosphorus. Apropos of a series of 303 patients followed for 12 to 24 years].

Three hundred and three cases of polycythaemia vera were treated between 1949 and 1961 using radioactive phosphorus, the minimum follow-up for the patients in the group being 12 years and the maximum 24 years. Two hundred and thirty three patients died, the median duration of survival after the first treatment with phosphorus being 10 years (i.e. 12 years after the diagnosis was made). 59 patients died of the vascular complications of polycythaemia, 76 of leukaemia or myelofibrosis. The total number of deaths due to vascular complications up to the tenth year exceeded the total number of deaths due to haematological complications (leukaemia or myeloid metaplasia). At the end of the 11th year the opposite was true. From the ninth year onwards, acute leukaemia and myelofibrosis represent more than 40 p.cent of deaths of known cause and the annual probability of death from a haematological cause for the surviving patients increases regularly until the fifteenth year when it reaches approximately 5 p.cent of the patients at risk. However the median survival of patients dying from acute leukaemia or myeloid splenomegaly is slightly longer than that of patients dying from other causes, this confirming that these disorders would appear to represent the terminal phase in the course of polycythaemia vera.