Essential Thrombocythemia Clinical Considerations

Accurate Diagnosis Is a Key Factor in Clinical Decision-Making

ET may be difficult to diagnose because of its similarity to other MPNs,1 and misdiagnosis can have an impact on patient outcomes.2 The International Working Group for MPN Research and Treatment (IWG-WRT) subjected 1,104 cases of locally diagnosed ET to review by a central laboratory. The laboratory determined that 891 of the cases met the WHO criteria for ET, but 213 did not. They classified these cases as early/prefibrotic myelofibrosis. In terms of outcomes, these patients had worse overall survival, higher rates of transformation to leukemia, and higher rates of fibrotic progression. They also had a higher risk of bleeding.2 These results reinforce the importance of performing an accurate bone marrow biopsy for the differential diagnosis of ET from early/prefibrotic myelofibrosis.

ET remains an incurable disease. The focus of managing the disease is to3,4:

  • Avoid first occurrence and/or recurrence of thrombotic and bleeding complications
  • Minimize the risk of acute leukemia and post–PV myelofibrosis
  • Control systemic symptoms
  • Treat complications (thrombosis and hemorrhage)
  • Manage risk situations (eg, pregnancy, surgery)

1. Tefferi A, Vardiman JW. Leukemia. 2008;22:14-22. 2. Barbui T, Thiele J, Passamonti F, et al. J Clin Oncol. 2011;29:3179-3184. 3. Beer PA, Green AR. Hematology Am Soc Hematol Educ Program. 2009:621-628. 4. Barbui T, Barosi G, Birgegard G, et al. J Clin Oncol. 2011;29:761-770.