32P TREATMENT OF POLYCYTHEMIA WITH OR WITHOUT HYDROXY-UREA MAINTENANCE THERAPY - PRELIMINARY-RESULTS SINCE 1980 IN 237 ELDERLY OR HIGH VASCULAR RISK SUBJECTS

Between 1980 and 1992, 237 polycythaemic patients aged 65 or more, or with high vascular risk factors were treated with 32P according to a p rotocol using, or not, maintenace therapy with low-dose hydroxy-urea ( 500 mg/day). The present follow-up covers 1448 years/patient. Maintena nce therapy was seldom discontinued because of blood toxicity or gastr ointestinal intolerance, but it was stopped in 20 percent of the cases because monitoring was difficult in very old patients. Maintenance th erapy reduced the mean annual 32P dose by at least 50 percent. However , the actual risk of malignant blood diseases (myelodysplasia, acute l eukaemia, lymphoma) was similar in the two arms of the protocol: 14 pe rcent at the 10th year. Compared with the French population of the sam e age-groups, there was no excess of epithelial cancers in both arms. Maintenance therapy did not control platelet counts perfectly, The ris k of severe vascular events was identical in both arms; probably no hi gher than expected at that age and significantly lower than in previou sly published data. The actuarial survival curves in both groups showe d a 50 percent survival of about 11 years, i.e. very near to that of t he reference French population (12.5 years) of similar sex and age.