Myeloproliferative disorders: complications, survival and causes of death

This retrospective single-center study compared thromboembolic and hemorrha gic complications, survival and causes of death in a cohort of 102 consecut ive patients with myeloproliferative disorders (MPD). We included 17 patien ts with essential thrombocythemia (ET), 59 with polycythemia vera (PV), and 26 with osteomyelofibrosis (OMF). The median follow-up was 3.7 years. Esti mated 8-year probability of complications for the entire cohort was 80+/-11 % (95% confidence interval), without significant differences among MPD subg roups. The rate of thromboembolic complications, expressed as the number of events per 100 patient years, was 16.7 for patients with PV, 13.8 for OMF, and 7.5 for ET. Fifty-four percent of thromboembolic events in PV involved cerebral or limb arteries. The rate of bleeding complications was highest in patients with OMF (31.8 per 100 patient years), followed by ET and PV (1 1.8). Ninety percent of bleeding episodes affected the skin, mucosal membra nes, and the gastrointestinal tract. Eight-year survival was highest in ET with 91+/-17%, followed by PV (66+/-18%) and OMF (40+/-31%) (P<0.01). Twent y-four patients died during the observation period, and fatal thrombosis (i n five patients) represented the leading cause of death. Only two patients with MPD died from fatal hemorrhage and one from acute leukemia. We conclud e that survival is highest in ET and lowest in OMF. Both thromboembolic and hemorrhagic complications are frequent. However, thrombosis appears to be more often fatal than bleeding complications. Prophylaxis of thromboembolic events remains a key issue in the management of MPD.