- Essential Thrombocythemia
Essential Thrombocythemia (ET)
Essential thrombocythemia (ET) the MPN associated with the most favorable outcome is characterized by thrombocytosis and proliferation of enlarged, mature megakaryocytes.1 It has an annual incidence of 1.5-2 per 100,000 persons.2
ET is caused by dysregulated Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway activation, resulting in an excessive production of platelets that can lead to cardiovascular and hemorrhagic complications.1,3,4
Patients with ET can present with a variety of clinical manifestations.1
The median survival of patients with ET is 10-15 years.1 In a minority of patients, the disease can progress to myelofibrosis (MF) or acute myeloid leukemia (AML).1
Although the median age at diagnosis is 50-60 years, many of the patients diagnosed are women around age 30.1
- Swerdlow SH, Campo E, Harrison NL, et al. WHO classification of tumours of haematopoietic and lymphoid tissues. Vol 2. 4th ed. Geneva: World Health Organization; 2008.
- Barbui T, Finazzi G, Carobbio A, et al. Development and validation of an international prognostic score of thrombosis in world health organization-essential thrombocythemia (IPSET-thrombosis). Blood. 2012;120(26):5128-33; quiz 5252.
- Bazzan M, Tamponi G, Schinco P, et al. Thrombosis-free survival and life expectancy in 187 consecutive patients with essential thrombocythemia. Ann Hematol. 1999;78(12):539-543.
- Levine RL, Pardanani A, Tefferi A, Gilliland DG. Role of JAK2 in the pathogenesis and therapy of myeloproliferative disorders. Nat Rev Cancer. 2007;7(9):673-683.
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- Falanga A, Marchetti M, Vignoli A, Balducci D, Barbui T. Leukocyte-platelet interaction in patients with essential thrombocythemia and polycythemia vera. Exp Hematol. 2005;33(5):523-530.
- Scherber R, Dueck AC, Johansson P, et al. The myeloproliferative neoplasm symptom assessment form (MPN-SAF): International prospective validation and reliability trial in 402 patients. Blood. 2011;118(2):401-408.
- Palandri F, Polverelli N, Catani L, Ottaviani E, Baccarani M, Vianelli N. Impact of leukocytosis on thrombotic risk and survival in 532 patients with essential thrombocythemia: A retrospective study. Ann Hematol. 2011;90(8):933-938.
- Carobbio A, Finazzi G, Guerini V, et al. Leukocytosis is a risk factor for thrombosis in essential thrombocythemia: Interaction with treatment, standard risk factors, and Jak2 mutation status. Blood. 2007;109(6):2310-2313.
- Tefferi A, Barbui T. Personalized management of essential thrombocythemia—application of recent evidence to clinical practice. Leukemia. 2013;27:1617-1620.
- Beer PA, Erber WN, Campbell PJ, Green AR. How I treat essential thrombocythemia. Blood. 2011;117(5):1472-1482.
- Tefferi A. Novel mutations and their functional and clinical relevance in myeloproliferative neoplasms: JAK2, MPL, TET2, ASXL1, CBL, IDH and IKZF1. Leukemia. 2010;24(6):1128-1138.
- Abdel-Wahab O, Pardanani A, Bernard OA, et al. Unraveling the genetic underpinnings of myeloproliferative neoplasms and understanding their effect on disease course and response to therapy: Proceedings from the 6th international post-ASH symposium. Am J Hematol. 2012;87(5):562-568.
- Rumi E, Pietra D, Guglielmelli P, et al. Acquired copy-neutral loss of heterozygosity of chromosome 1p as a molecular event associated with marrow fibrosis in MPL-mutated myeloproliferative neoplasms. Blood. 2013;121:4388-4395.
- Nangalia J, Massie CE, Baxter EJ, et al. Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2. N Engl J Med. 2013;369(25):2391-2405.
- Tefferi A, Guglielmelli P, Larson DR, et al. Long-term survival and blast transformation in molecularly-annotated essential thrombocythemia, polycythemia vera and myelofibrosis. Blood. 2014;124:2507-2513.
- Wolanskyj AP, Schwager SM, McClure RF, Larson DR, Tefferi A. Essential thrombocythemia beyond the first decade: Life expectancy, long-term complication rates, and prognostic factors. Mayo Clin Proc. 2006;81(2):159-166.
- Carobbio A, Thiele J, Passamonti F, et al. Risk factors for arterial and venous thrombosis in WHO-defined essential thrombocythemia: An international study of 891 patients. Blood. 2011;117(22):5857-5859.
- Passamonti F, Thiele J, Girodon F, et al. A prognostic model to predict survival in 867 world health organization-defined essential thrombocythemia at diagnosis: A study by the international working group on myelofibrosis research and treatment. Blood. 2012;120(6):1197-1201.
- 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.
- Gangat N, Wolanskyj AP, McClure RF, et al. Risk stratification for survival and leukemic transformation in essential thrombocythemia: A single institutional study of 605 patients. Leukemia. 2007;21(2):270-276.
- Barbui T, Thiele J, Passamonti F, et al. Survival and disease progression in essential thrombocythemia are significantly influenced by accurate morphologic diagnosis: An international study. J Clin Oncol. 2011;29(23):3179-3184.