Life expectancy of patients with essential thrombocythaemia (ET) is reported to be modestly reduced compared with that of the general population. Median overall survival (stratified by age) has been estimated to be:[68]Szuber N, Vallapureddy RR, Penna D, et al. Myeloproliferative neoplasms in the young: Mayo Clinic experience with 361 patients age 40 years or younger. Am J Hematol. 2018 Dec;93(12):1474-84.
https://www.doi.org/10.1002/ajh.25270
http://www.ncbi.nlm.nih.gov/pubmed/30157297?tool=bestpractice.com
Median overall survival (all aged) for patients with ET was 12.1 years in one study, based on registry data for 8,768 patients diagnosed between 2001 and 2015 (median follow-up 5.8 years). During the study period, 134 (1.5%) ET patients progressed to acute myeloid leukaemia (AML); median time to AML transformation was 5.8 years.[69]Smith CJ, Thomas JW, Ruan G, et al. A population-based study of outcomes in polycythemia vera, essential thrombocythemia, and primary myelofibrosis in the United States from 2001 to 2015: comparison with data from a Mayo Clinic single institutional series. Am J Hematol. 2021 Dec 1;96(12):E464-8.
https://onlinelibrary.wiley.com/doi/10.1002/ajh.26377
Development of either AML or myelofibrosis is uncommon. The 15-year cumulative risk of transformation to AML or myelofibrosis has been reported to be in the range of 2% to 5.3% and 4% to 11%, respectively.[70]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 Aug 10;29(23):3179-84.
http://www.ncbi.nlm.nih.gov/pubmed/21747083?tool=bestpractice.com
[71]Cerquozzi S, Tefferi A. Blast transformation and fibrotic progression in polycythemia vera and essential thrombocythemia: a literature review of incidence and risk factors. Blood Cancer J. 2015 Nov 13;5:e366.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4670948
http://www.ncbi.nlm.nih.gov/pubmed/26565403?tool=bestpractice.com
[72]Passamonti F, Rumi E, Pungolino E, et al. Life expectancy and prognostic factors for survival in patients with polycythemia vera and essential thrombocythemia. Am J Med. 2004 Nov 15;117(10):755-61.
http://www.ncbi.nlm.nih.gov/pubmed/15541325?tool=bestpractice.com
Janus kinase 2 (JAK2), calreticulin (CALR), or myeloproliferative leukaemia virus oncogene (MPL) mutation status does not affect survival in patients with ET.[39]Tefferi A, Vannucchi AM, Barbui T. Essential thrombocythemia: 2024 update on diagnosis, risk stratification, and management. Am J Hematol. 2024 Apr;99(4):697-718.
https://onlinelibrary.wiley.com/doi/10.1002/ajh.27216
http://www.ncbi.nlm.nih.gov/pubmed/38269572?tool=bestpractice.com
However, JAK2 and MPL mutations have been associated with higher risk of arterial thrombosis. MPL mutations have also been associated with fibrotic progression.