Blast phase of essential thrombocythemia: A single center study

Abstract

Blast phase (BP) may occur as a late event in essential thrombocythemia (ET). This study includes 19 patients with post-ET BP diagnosed and followed in a single institution. At BP, 63% of patients had leukocytosis (white blood cell count >10 3 10 9 /L), 74% had anemia (hemoglobin value <10 g/dL), 74% had thrombocytopenia (platelet count <100 3 10 9 /L), and 84% were over 65 years of age. Cytogenetic analysis was available in 10 patients: six had karyotype aberrations. According to cytogenetic-based risk stratification of de novo acute leukemia (AL), all patients had an unfavorable profile. JAK2 (V617F) mutational status was evaluated in five patients. In two of them, the JAK2 mutation was undetectable in blast cells (one with JAK2-positive ET), whereas in three both granulocytes and blast cells displayed the mutation. Treatment of BP was patient-based according to the performance status and co-morbidities and consisted of palliation in 14 patients, and of induction of remission in five. Median survival was 2.3 months (range 0.2-22.3), irrespective of the treatment received. In conclusion, this study indicates that AL evolved from ET has unfavorable clinical and biological features. JAK2 (V617F)-positive ET may evolve in few instances into JAK2-negative leukemia. The outcome of patients is poor whatever the treatment used. Am. J. Hematol. 84:641-644, 2009. V

Correction of Anemia and Evaluation of Efficacy of Red Blood Cell Transfusion in Patients with Oncohematological Diseases

“…У пациентов с неходжкинскими лимфомами в первые 2-3 цикла химиотерапии частота анемии возрастает с 34,9 до 73,7 %, с хроническим лим-фолейкозом -с 30,1 до 72,9 %, со множественной миеломой -с 56 до 77,4 % [3][4][5]. Еще чаще анемия наблюдается при острых лейкозах, миелодиспласти-ческих синдромах (60-98 %), первичном миелофи-брозе (38 %), эссенциальной тромбоцитемии в фазе бластного криза (74 %), хроническом миелолейкозе (у 40-83 % больных, получающих терапию ингибито-рами тирозинкиназы) [2,[6][7][8][9][10].…”

New generation small-molecule inhibitors in myeloproliferative neoplasms

“…All three diseases have a higher risk of developing thrombosis [2,3]. Polycythemia vera and essential thrombocythemia may progress to myelofibrosis [4], named post-polycythemia vera and postessential thrombocythemia myelofibrosis [5], and all may progress to acute myeloid leukemia (AML) [6][7][8]. The discovery of the V617F somatic gain-offunction mutation in the JAK2 gene (detectable in $95% of polycythemia vera and in approximately 60% of PMF and essential thrombocythemia) [9,10] has been rapidly followed by the identification of other mutations relevant to disease pathogenesis, typically targeting genes involved in tyrosine kinase signaling, such as MPL, CBL and LNK [11][12][13].…”

How to manage polycythemia vera

“…25,26 A leukocyte count 415 Â 10 9 /l was associated with myocardial infarction in the ECLAP trial, 27 and with counts 49.5 Â 10 9 /l with thrombosis in 187 PV and ET cases; 28 conversely, no correlation has been found in 407 low-risk ET and PV patients from the Mayo Clinic. 29 Regarding the incidence of late events as AML 30,31 and post-PV MF, I mention to patients the following figures: a 15-year cumulative risk of 7% and 6% for AML and post-PV MF, respectively. 32 These events are very difficult to predict, but I discuss the association of post-PV MF with leukocytosis 415 Â 10 9 /l 1 and with higher JAK2 (V617F) allele burden, but I advise patients that this information needs to be confirmed by other trials.…”