Current challenges in the management of essential thrombocythemia

Essential thrombocythemia (ET), an uncommon blood cancer, is one of the classic myeloproliferative neoplasms, a category that also includes polycythemia vera and primary myelofibrosis. All 3 diseases are clonal hematopoietic stem cell disorders. Since 2005, when scientists discovered a molecular aberration driving clonal hematopoiesis in polycythemia vera, our understanding of the genomic underpinnings of these conditions has increased rapidly. Over the last decades, primary prevention of thrombotic and hemorrhagic complications has improved the lives of patients with ET, and the ability to characterize the disease by the presence or absence of molecular mutations has lent precision to our prognostic models. This review outlines a modern approach to the diagnosis and treatment of ET. It highlights the 2016 World Health Organization standards for differentiating the disease from primary myelofibrosis, which is key for an accurate prognosis. It also describes the current risk stratification models and discusses the vascular and hemorrhagic risks that affect patients with this chronic condition, including younger individuals and pregnant women. Finally, it outlines a simple-to-follow treatment algorithm that is based on an understanding of the vascular risks and provides a foundation for discussing treatment choices with patients.