Treatment of Polycythemia Vera

Introduction to Treatment Approaches

The American Society of Clinical Oncology recommends phlebotomy to maintain hematocrit below 45%, combined with low-dose aspirin, for all patients with polycythemia vera (PV), while essential erythrocytosis primarily requires treatment of the underlying cause with higher hematocrit targets (up to 52-55%) being acceptable 1, 2

Phlebotomy should be performed to maintain hematocrit strictly below 45% in men, with corresponding values for females and other races, as recommended by the European LeukemiaNet 1, 3
Low-dose aspirin (100mg daily) is recommended for all patients without contraindications, as it significantly reduces cardiovascular events, according to the Journal of Clinical Oncology 1, 4

Cytoreductive therapy should be added for high-risk patients, defined as those with age >60 years and/or history of thrombosis, as recommended by the American Society of Hematology 1, 3
Poor tolerance of phlebotomy or frequent phlebotomy requirement, symptomatic or progressive splenomegaly, severe disease-related symptoms, platelet counts >1,500 × 10^9/L, and progressive leukocytosis are also indications for cytoreductive therapy 4

Hydroxyurea (starting dose 500mg twice daily) is recommended for older patients (>40 years) by the Mayo Clinic Proceedings 5, 1
Interferon-α (starting dose 3 million U subcutaneously 3 times weekly) is preferred for younger patients (<40 years) and women of childbearing age, as recommended by the Annals of Oncology 5, 3

The focus should be on identifying and treating the underlying cause, with phlebotomy considered when hematocrit exceeds 52-55%, rather than the stricter <45% target used in PV, as recommended by the Praxis Medical Insights 2

The European LeukemiaNet criteria should be adopted for defining clinicohematologic response in PV 1
Resistance or intolerance to hydroxyurea is defined as the need for phlebotomy to keep hematocrit <45% after 3 months of at least 2g/day of hydroxyurea, uncontrolled myeloproliferation, failure to reduce massive splenomegaly or relieve splenomegaly-related symptoms, or cytopenia or unacceptable side effects at any dose, as recommended by the Journal of Clinical Oncology 1