Developments in diagnosis and treatment of essential thrombocythemia

ABSTRACT

Introduction: Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm characterized by thrombocytosis, increased risk of thrombotic/hemorrhagic events and clonal evolution into blast phase or myelofibrosis.

Areas covered: The authors will discuss biology, diagnosis, prognosis, therapy, and outcome of ET. An accurate molecular-morphologic assessment is necessary in order to properly establish diagnosis and prognosis of ET. Stratification for thrombosis prediction is essential, and IPSET-t model is widely applied. The current treatment strategy is directed to lower the rate of vascular events using cytoreduction in patients at high risk. Prophylactic low dose aspirin indication is more uncertain. To date, therapies for patients who are resistant or intolerant to first-line treatments are scarce. Overall, life expectancy indicates an indolent disease, but IPSET model helps in predicting survival at the time of diagnosis.

Expert opinion: Challenging for the future will be to share criteria for ET diagnosis with the community. New insights into the molecular pathogenesis of the disease will improve the prediction of clonal evolution and outcome, and lead to the use of disease-modifying treatments.

KEYWORDS:

• Essential thrombocythemia
• myelofibrosis
• JAK2
• JAK inhibitor
• thrombosis
• survival

Article highlights

• Essential thrombocythemia is a clonal disease, with JAK2, CALR and MPL mutations as driver events. The 2017 WHO classification recognizes new diagnostic criteria.

• The IPSET model predicts survival, while the IPSET-t predicts thrombosis risk. Hydroxyurea and interferons are first-line therapies, while interferons (if Hydroxyurea first) and anagrelide represent second-line options.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This study was supported by grants of the Fondazione Regionale Ricerca Biomedica, Milan, Italy [FRRB project no. 2015-0042, Genomic profiling of rare hematologic malignancies, development of personalized medicine strategies, and their implementation into the Rete EmatologicaLombarda (REL) clinical network], by Fondazione Matarelli (Milano, Italy), Fondazione Rusconi (Varese, Italy) and AIL Varese ONLUS.