Changes to This Summary (04/11/2014)
The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.
Revised summary title to read Chronic Myeloproliferative Neoplasms.
Added text to state that chronic myeloproliferative neoplasms (MPN) usually occur sporadically; however, familial clusters of MPNs have been reported. These familial clusters include autosomal-dominant inheritance and autosomal-recessive inheritance (cited Ranjan et al. as reference 1).
Revised text to state that age older than 65 years, leukocytosis, and a history of vascular events are associated with poor prognosis (cited Bonicelli et al. as reference 9).
Revised text to state that in two prospective, randomized trials, 528 higher-risk patients were randomly assigned to ruxolitinib or to either placebo. At 48 weeks, patients on ruxolitinib had a decrease of 30% to 40% in mean spleen volume compared with an increase of 7% to 8% in the control patients (cited Harrison et al. as reference 28 and level of evidence 1iiDiv and Verstovsek et al. [New England Journal of Medicine 2012] as reference 29 and level of evidence 1iDiv). Ruxolitinib also improved overall quality-of-life measures, with low toxic effects in both studies, but with no benefit in overall survival in the initial reports. Additionally stated that follow-up in both studies showed a survival benefit among ruxolitinib-treated patients compared with control patients (cited Verstovsek et al. [Haematologica 2013] as reference 30 and Cervantes et al. as reference 31 and level of evidence 1iiA). Clinical benefits were observed across a wide variety of clinical subgroups (cited Mascarenhas et al. and Verstovsek et al. [British Journal of Haematology 2013] as references 32 and 33, respectively). Further revision to text stated that ruxolitinib does not reverse bone marrow fibrosis or induce histologic or cytogenetic remissions. More selective JAK inhibitors are currently being evaluated in clinical trials (cited Verstovsek et al. [Journal of Clinical Oncology 2011] and Tefferi as references 35 and 36, respectively).
Revised text to state that allogeneic stem cell transplantation is the only potentially curative treatment available, but the associated morbidity and mortality limit its use to younger, high-risk patients (cited Alchalby et al. as reference 54).
Revised text to include the United Kingdom (UK) as the location of the trial that compared hydroxyurea plus aspirin with anagrelide plus aspirin. Also revised text to state that no differences were seen for subsequent myelodysplasia or acute leukemia in this trial (added level of evidence 1iiD).
Added text to state that a prospective, randomized, central European trial compared hydroxyurea and anagrelide in 259 previously untreated and high-risk patients; the diagnosis of essential thrombocythemia was made by the World Health Organization (WHO) recommendations, not by the Polycythemia Vera Study Group criteria as in the UK study. Added that patients with leukocytosis and a diagnosis of early prefibrotic myelofibrosis were excluded from the central European trial; therefore, in this analysis, there were no differences in outcome for thrombotic or hemorrhagic events (cited Gisslinger et al. as reference 13 and level of evidence 1iiD).
Added text to state that the three randomized, prospective trials establish the efficacy and safety for the use of hydroxyurea for patients with high-risk essential thrombocythemia, therefore, for patients diagnosed by WHO standards, anagrelide represents a reasonable alternative therapy. Added that the addition of aspirin to cytoreductive therapies like hydroxyurea or anagrelide remains controversial, but a retrospective anecdotal report suggested reduction in thrombosis for patients older than 60 years (cited Alvarez-Larrán as reference 14).
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