Management of polycythemia vera in the community oncology setting

Polycythemia vera, classified as a myeloproliferative neoplasm (MPN) and characterized by uncontrolled, clonal, myeloid expansion with predominant erythrocytosis,1 affects about 100,000 individuals in the United States.2 It is a chronic and burdensome disease associated with shortened survival.3 Patients are at an increased risk of cardiovascular events, solid tumors, and transformation to myelofibrosis (MF) and/or acute myeloid leukemia (AML).4,5 Furthermore, patients generally have a reduced quality of life (QoL) stemming from prevalent and occasionally severe polycythemia vera–related signs and symptoms, including fatigue, pruritus, and splenomegaly.6 In general, the classical Philadelphia chromosome-negative MPNs are associated with driver mutations in the following three genes: Janus kinase 2 (JAK2), calreticulin (CALR), and myeloproliferative leukemia virus oncogene (MPL).7 Almost all patients with polycythemia vera have an activating mutation in the cytoplasmic signal transduction protein JAK2.4 Patients with essential thrombocythemia (ET) or MF can have mutations in JAK2, CALR, or MPL. However, CALR and MPL mutations are absent or exceedingly rare in patients with polycythemia vera.7 Diagnosis can be challenging and is currently based on 2016 World Health Organization (WHO) diagnostic criteria.1 Management strategies include the use of aspirin, phlebotomy, and cytoreductive therapy. Ruxolitinib is a newer treatment option available for patients with polycythemia vera who are either resistant to or intolerant of hydroxyurea8,9— a population that previously had few treatment options. It is important for community oncologists and other treating clinicians to understand current diagnostic strategy and management options based on established guidelines, recent clinical evidence, and regulatory updates.