First-Line Therapy and Special Issues Management in Polycythemia Vera and Essential Thrombocythemia

Recommendations for management of polycythemia vera (PV) and essential thrombocythemia (ET) are based on a limited number of randomized clinical and on several observational studies describing the clinical course of the diseases and indirectly evaluating the role of different treatments. According to European LeukemiaNet (ELN) recommendations published in 2011, first-line therapy in all patients with PV should be phlebotomy to maintain the hematocrit less than 45% and low-dose aspirin (75–100 mg). Cytoreduction is strongly indicated in high-risk cases defined by age and previous major vascular events. In patients with PV, initially defined at low risk, poor tolerance to or high need of phlebotomy, symptomatic or progressive splenomegaly, severe disease-related symptoms, platelet counts greater than 1.5 × 109/L, or progressive leukocytosis are indications for cytoreductive therapy. Either hydroxyurea or interferon alpha is the first-line therapy at any age. Intermittent busulfan may be considered in elderly patients. No cytoreductive drugs in otherwise low-risk patients carrying well-controlled cardiovascular risk factors is recommended. All patients with ET presenting microvascular disturbances should be managed with low-dose aspirin (75–100 mg). Cytoreduction with HU is the first-line therapy in high-risk patients at any age. The use of cytoreductive drugs in otherwise low-risk patients carrying well-controlled cardiovascular risk factors is not generally indicated.