How to manage essential thrombocythemia.

I use the hematological, morphological and molecular criteria recently established by the World Health Organization to diagnose essential thrombocytemia. In these patients, major causes of morbidity and mortality are represented by thrombosis and bleeding, whereas progression to myelofibrosis and transformation to acute leukemia are more rare. Myelosuppressive therapy can reduce the rate of vascular complications, but there is some concern about treatment-related toxicity. Therefore, I follow a risk-oriented therapeutic approach to avoid inappropriate exposure to cytotoxic drugs on one side or suboptimal treatment on the other. Established predictors of cardiovascular events are represented by older age and previous thrombosis, whereas recent data suggest a prognostic role for novel risk factors, including leukocytosis and JAK2V617F mutational status. There is no indication for therapeutic intervention in asymptomatic, low-risk patients, while I treat high-risk patients with hydroxyurea (HU) first. Other therapeutic options, such as interferon alpha or anagrelide, may find place in selected patients including those who are resistant or intolerant to HU. I follow a risk-oriented approach also for management of pregnancy. Low-risk women are given low-dose aspirin throughout pregnancy and prophylactic low-molecular-weight heparin (LMWH) post partum, whereas LMWH throughout pregnancy and/or interferon-alpha can be required in high-risk cases.