Polycythemia Vera (PV): Causes, Symptoms & Complications
About polycythemia vera
Polycythemia vera is a rare and incurable blood cancer associated with an overproduction of blood cells in the bone marrow that affects up to three people per 100,000 globally.1,2 This condition is part of a group of related blood cancers known as myeloproliferative neoplasms (MPNs).1 The exact causes of polycythemia vera are unknown; however, almost all patients have a mutation in the Janus kinase 2 (JAK 2) gene, which can cause a dysregulation and overproduction of blood cells.1
Polycythemia vera is typically characterized by an elevated hematocrit, a measure of the volume percentage of red blood cells in whole blood and often associated with an increase of white blood cells and platelets. Signs, symptoms and complications of polycythemia vera result from too many red blood cells. An abundance of red blood cells can lead to a thickening of the blood and an increased risk of clots, which can cause serious cardiovascular complications.1 Additionally, patients with polycythemia vera may have an enlarged spleen and symptoms that are frequent and burdensome, with an overall impact on quality of life similar to that seen with myelofibrosis.3,4 Polycythemia vera can persist for many years and in some cases evolve to myelofibrosis (post-PV MF) or acute myeloid leukemia (AML).5
Treating polycythemia vera
For most people, polycythemia vera treatment does not cure the disease. The treatment goal is to control the risk of cardiovascular complications and disease progression as well as to control symptoms. Common types of polycythemia vera treatments include:1,6,7
Phlebotomy: A procedure to remove blood from the body to reduce the concentration of red blood cells, which is used to help maintain a hematocrit level below 45%. However, phlebotomy is usually unsuitable as a permanent treatment option due to its inability to control symptoms or effectively manage the overproduction of red blood cells.
Cytoreductive therapy: Typically used to treat high-risk polycythemia vera patients when phlebotomy is unable to control symptoms and blood counts alone. Some patients become resistant or intolerant to therapy and are considered to have uncontrolled disease.8
Questions to ask your doctor
When you are diagnosed with polycythemia vera, you may want to ask your doctor questions like these about your diagnosis and treatment plan:
What are the symptoms and complications of polycythemia vera?
Why is hematocrit control important in polycythemia vera?
What is inadequately controlled polycythemia vera?
What are my treatment choices?
What are the expected benefits of each kind of treatment?
What are the risks of each treatment?
What are the side effects of each treatment?
How will we know if treatment is working?
How will each treatment affect my daily life?
Are there new treatments or clinical trials that I should consider?
Titmarsh G, Duncombe A, McMullin M, et al. How Common are Myeloproliferative Neoplasms? A Systematic Review and Meta-analysis. Am. J. of Hematol. 2014:1-7.
Emanuel R, Dueck A, Geyer H, et al. Myeloproliferative Neoplasm (MPN) Symptom Assessment Form Total Symptom Score: Prospective International Assessment of an Abbreviated Symptom Burden Scoring System Among Patients with MPNs. J Clin Oncol. 2012;30(33):4098-4103.
Mesa RA, Niblack J, Wadleigh M, et al. The Burden of Fatigue and Quality of Life in Myeloproliferative Disorders (MPDs): An International Internet-based Survey of 1,179 MPD Patients. Cancer. 2007;109(1):68-76.
Passamonti F, et al. Life Expectancy and Prognostic Factors for Survival in Patients with Polycythemia Vera and Essential Thrombocythemia. Am J of Med. 2004;117:755-761.
Barbui T, Barosi G, Birgegard G, et al. Philadelphia-Negative Classical Myeloproliferative Neoplasms; Critical Concepts and Management Recommendations from European LeukemiaNET. J Clin Oncol. 2011;29(6):761-770.
Finazzi G and Barbui T. How I Treat Patients with Polycythemia Vera. Blood. 2007; 109(12):5104-5111.
Alvarez-Larran A, Pereira A, Cervantes F, et al. Assessment and Prognostic Value of The European Leukemianet Criteria for Clinicohematologic Response, Resistance,and Intolerance to Hydroxyurea in Polycythemia Vera. Blood. 2012;119(6):1363-1369.