Risk stratification, staging, and treatment of patients with polycythemia vera: Italian and European collaboration on low-dose aspirin in polycythemia data.

The clinical course of polycythemia vera (PV) is marked by a high incidence of thrombotic complications, which represent the main cause of morbidity and mortality. Major predictors of vascular events are increasing age and previous thrombosis. Myelosuppressive drugs can reduce the rate of thrombosis, but there is concern that their use increases the risk of transformation into acute leukemia. To tackle this dilemma, a risk-oriented management strategy is recommended. Low-risk patients should be treated with phlebotomy and low-dose aspirin based on the results of the European Collaboration on Low-Dose Aspirin in Polycythemia study. Cytotoxic therapy is indicated in high-risk patients, and the drug of choice is hydroxyurea because its leukemogenicity is low. New therapeutic options, that theoretically are devoid of leukemic risk (such as interferon alpha and imatinib), should be reserved for selected patients and require additional clinical experience.