IDH2 mutations in patients with normal karyotype AML predict favorable responses to daunorubicin, cytarabine and cladribine regimen.

Mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) genes occur in about 20% patients with acute myeloid leukemia (AML), leading to DNA hypermethylation and epigenetic deregulation. We assessed the prognostic significance of IDH1/2 mutations (IDH1/2+) in 398 AML patients with normal karyotype (NK-AML), treated with daunorubicine + cytarabine (DA), DA + cladribine (DAC), or DA + fludarabine. IDH2 mutation was an independent favorable prognostic factor for 4-year overall survival (OS) in total NK-AML population (p = 0.03, censoring at allotransplant). We next evaluated the effect of addition of cladribine to induction regimen on the patients' outcome according to IDH1/2 mutation status. In DAC group, 4-year OS was increased in IDH2+ patients, compared to IDH-wild type group (54% vs 33%; p = 0.0087, censoring at allotransplant), while no difference was observed for DA-treated subjects. In multivariate analysis, DAC independently improved the survival of IDH2+ patients (HR = 0.6 [0.37-0.93]; p = 0.024; censored at transplant), indicating that this group specifically benefits from cladribine-containing therapy. In AML cells with R140Q or R172K IDH2 mutations, cladribine restrained mutations-related DNA hypermethylation. Altogether, DAC regimen produces better outcomes in IDH2+ NK-AML patients than DA, and this likely results from the hypomethylating activity of cladribine. Our observations warrant further investigations of induction protocols combining cladribine with IDH1/2 inhibitors in IDH2-mutant.

CEBPA copy number variations in normal karyotype acute myeloid leukemia: Possible role of breakpoint-associated microhomology and chromatin status in CEBPA mutagenesis.

Copy number variations (CNV) in CEBPA locus represent heterogeneous group of mutations accompanying acute myeloid leukemia (AML). The aim of this study was to characterize different CEBPA mutation categories in regard to biological data like age, cytology, CD7, and molecular markers, and identify possible factors affecting their etiology. We report here the incidence of 12.6% of CEBPA mutants in the population of 262 normal karyotype AML (NK-AML) patients. We confirmed that double mutant AMLs presented uniform biological features when compared to single CEBPA mutations and accompanied mostly younger patients. We hypothesized that pathogenesis of distinct CEBPA mutation categories might be influenced by different factors. The detailed sequence analysis revealed frequent breakpoint-associated microhomologies of 2 to 12bp. The analysis of distribution of microhomology motifs along CEBPA gene showed that longer stretches of microhomology at the mutational junctions were relatively rare by chance which suggests their functional role in the CEBPA mutagenesis. Additionally, accurate quantification of CEBPA transcript levels showed that double CEBPA mutations correlated with high-level CEBPA expression, whereas single N-terminal CEBPA mutations were associated with low-level CEBPA expression. This might suggest that high-level CEBPA expression and/or accessibility of CEBPA locus contribute to B-ZIP in-frame duplications.

Demographic, Hematologic, and Clinical Features of Myelodysplastic Syndrome Patients: Results from the First Polish Myelodysplastic Syndrome Registry.

Epidemiological studies on myelodysplastic syndromes (MDS) in Middle-Eastern Europe are scarce. No data about the demographic, clinical, and laboratory features of Polish MDS patients have been published. The aim of this study was to assess the epidemiological data and toxic exposure of Polish MDS patients and their association with hematological parameters and clinical outcomes. For 15 months, 966 living MDS patients were enrolled at 24 centers (12 university and 12 community hospitals). Follow-up was conducted for the next 55 months. The percentage of patients older than 80 years (16%) was between the values for Eastern and Western countries. In patients younger than 55 years, a female predominance was observed (male/female ratio 0.70:1 vs. 1.29:1; p < 0.001). Female patients had higher platelet counts (160 × 109/l vs. 111 × 109/l; p < 0.001). Patients exposed to chemicals were younger than patients without such exposure; their median age at MDS diagnosis was 66 vs. 70 years (p = 0.037). Smokers had significantly lower hemoglobin concentrations (8.6 vs. 9.1 g/dl; p = 0.032) and lower platelet counts (99 × 109/l vs. 137 × 109/l; p < 0.001) than nonsmokers. We provide the first description of the characteristics of Polish MDS patients. Females predominated in the group aged <60 years and they had higher platelet counts. The course of the disease is affected by toxic exposure and smoking.

[Long-term survival results according to cytogenetic risk in patients with acute myeloid leukemia--singl center experience]. / Odlegle wyniki przezycia chorych na ostre bialaczki szpikowe w zaleznosci od grupy ryzyka cytogenetycznego--analiza jednoosrodkowa.

Cytogenetic analysis of leukemic blasts has become a part of the standard diagnosis approach of acute myeloid leukemia patients. Chromosomal aberrations findings separate AML patients into three broad prognostic categories: favorable, intermediate and high risk. We analyzed retrospectively 179 adults with de novo acute myeloid leukemia (AML), younger than 60 years admitted to our Department between January 1999 and April 2009 to evaluate the prognostic impact of cytogenetic abnormalities on complete remission (CR) rate, disease free survival (DFS), and overall survival (OS). All patients received similar induction therapy. Median follow-up of 3.8 years for favorable cytogenetic group CR rate was 85%, 3-year DFS was 70% and 3-year OS was 65%, for intermediate group CR rate, 3-year DFS and 3-year OS were respectively: 64%, 43%, and 38%. Among high risk patient CR rate was 40%, 3-year DFS was 24%, 3-year OS was 17%. We conclude that cytogenetics is among the most useful factors in predicting attainment of CR, DFS, and long-term overall survival in adult de novo AML patients younger than 60 years.