Chronic Myeloproliferative Disorders Treatment (PDQ®): Treatment - Health Professional Information [NCI] - Essential Thrombocythemia
In a case-controlled observational study of 65 low-risk patients (<60 years of age, platelet count <1,500 × 109 /L, and no history of thrombosis or hemorrhage) with a median follow-up of 4.1 years, the thrombotic risk of 1.91 cases per 100 patient years and hemorrhagic risk of 1.12 cases per 100 patient years was not increased over the normal controls. A prospective, randomized trial of 809 patients compared hydroxyurea plus aspirin with anagrelide plus aspirin. Although the platelet-lowering effect was equivalent, the anagrelide group had significantly more thrombotic and hemorrhagic events (hazard ratio [HR], 1.57; P = .03) and more myelofibrosis (HR, 2.92; P = .01). No differences were seen for myelodysplasia or acute leukemia.[Level of evidence: 1iiA] Many clinicians use hydroxyurea or platelet apheresis prior to elective surgery to reduce the platelet count and to prevent postoperative thromboembolism. No prospective or randomized trials document the value of this approach.
Among low-risk patients (defined as age 60 years or younger with no prior thrombotic episodes), a retrospective review of 300 patients showed benefit for antiplatelet agents in reducing venous thrombosis in JAK2-positive cases and in reducing arterial thrombosis in patients with cardiovascular risk factors. Balancing the risks and benefits of aspirin for low-risk patients can be difficult. In an extrapolation of the data from trials of p. vera, low-dose aspirin to prevent vascular events has been suggested, but there are no data from clinical trials to address this issue.
- No treatment, unless complications develop, if patients are asymptomatic, younger than 60 years, and have a platelet count of less than 1,500 × 109 /L.
- Interferon-alpha [16,17] or pegylated interferon-alpha.
Current Clinical Trials
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with essential thrombocythemia. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.
General information about clinical trials is also available from the NCI Web site.
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