MUTATIONAL ANALYSIS OF 231 DE NOVO AML PATIENTS BELOW 60 YEARS WITH CURATIVE THERAPY
(Abstract release date: 05/18/17)
EHA Library. Folta A. 05/18/17; 182364; PB1650
Adam Folta
Contributions
Contributions
Abstract
Abstract: PB1650
Type: Publication Only
Background
Acute myeloid leukemia (AML) is an aggressive cancer disease of the myeloid lineage of blood cells, characterized by rapid growth of undifferentiated myeloid precursors. Analysis of the spectrum of somatic mutations in leukemic cells may help to improve the identification of individual prognostic subgroups of patients as well as to observe clonal evolution in the course of AML treatment.
Aims
The aim of the project is to identify somatic alterations in genes related to AML using next generation sequencing (NGS) in large cohort of AML patients from Czech Republic and to determine their frequency and mutual coexistence.
Methods
The analyzed group consists of 231 de novo consecutively diagnosed AML patients with curative therapy below 60 years from five hematological centers. The NGS libraries are prepared from peripheral blood samples from diagnosis using ClearSeq AML panel (Agilent Technologies) and sequenced on MiSeq and NextSeq machines (Illumina). As positive are determined mutations with variant allele frequency (VAF) at least 2%.
Results
At least one somatic mutation (median 2; range 0-6) was identified in 204 (88.3%) patients with de novo AML. In total, 526 recurrent mutations in 19 genes were identified. The most frequently mutated genes were: FLT3 91/231 (39.4%; from this FLT3-ITD 69/231 [29.9%] and FLT3-TKD 22/231 [9.5%]), NPM1 90/231 (39.0%; mutation type A 71/90 [78.9%], type B 11/90 [11.1%], other types 10/90 [10.0%]), DNMT3A 68/231 (29.4%; mutations in codon R882 49/68 [72.1%]), NRAS 51/231 (22.0%; the most frequent mutation G12D 17/51 [22.0%]; 11/51 patients [21.6%] contain more than one mutation in NRAS gene), IDH2 35/231 (15.2%) and CEBPA 35/231 (15.2%). The analysis also identified mutations in rarely mutated genes U2AF1, SF3B1, EZH2 and SETBP1 in 4/231 (1.7%), 4/231 (1.7%), 1/231 (0.4%) and 1/231 (0.4%) samples, respectively.
Figure: Distribution of gene mutations with VAF ≥ 2% in AML cohort. Each column represents one patient (n = 231). Each row represents one gene described on left, on the right is shown the number of patients with mutation in the gene and its percentage from the total cohort. The color of the squares represents the status of the gene: red – single mutated, blue – double mutated, black – triple mutated, white/grey – no mutation.
Conclusion
The results of mutational analysis of large cohort of AML patients show high heterogeneity of detected mutations. Surprisingly we have detected high percentage of patients with mutations in gene NRAS. Together with sequencing results from the time of remission/relapse/resistance of the disease, the data will enable to get more complex view on the development of AML in time.
Supported by Ministry of Health of the Czech Republic, grant nr. 15-25809A, and by project MUNI/A/1106/2016. All rights reserved.
Session topic: 3. Acute myeloid leukemia - Biology
Keyword(s): mutation analysis, AML
Abstract: PB1650
Type: Publication Only
Background
Acute myeloid leukemia (AML) is an aggressive cancer disease of the myeloid lineage of blood cells, characterized by rapid growth of undifferentiated myeloid precursors. Analysis of the spectrum of somatic mutations in leukemic cells may help to improve the identification of individual prognostic subgroups of patients as well as to observe clonal evolution in the course of AML treatment.
Aims
The aim of the project is to identify somatic alterations in genes related to AML using next generation sequencing (NGS) in large cohort of AML patients from Czech Republic and to determine their frequency and mutual coexistence.
Methods
The analyzed group consists of 231 de novo consecutively diagnosed AML patients with curative therapy below 60 years from five hematological centers. The NGS libraries are prepared from peripheral blood samples from diagnosis using ClearSeq AML panel (Agilent Technologies) and sequenced on MiSeq and NextSeq machines (Illumina). As positive are determined mutations with variant allele frequency (VAF) at least 2%.
Results
At least one somatic mutation (median 2; range 0-6) was identified in 204 (88.3%) patients with de novo AML. In total, 526 recurrent mutations in 19 genes were identified. The most frequently mutated genes were: FLT3 91/231 (39.4%; from this FLT3-ITD 69/231 [29.9%] and FLT3-TKD 22/231 [9.5%]), NPM1 90/231 (39.0%; mutation type A 71/90 [78.9%], type B 11/90 [11.1%], other types 10/90 [10.0%]), DNMT3A 68/231 (29.4%; mutations in codon R882 49/68 [72.1%]), NRAS 51/231 (22.0%; the most frequent mutation G12D 17/51 [22.0%]; 11/51 patients [21.6%] contain more than one mutation in NRAS gene), IDH2 35/231 (15.2%) and CEBPA 35/231 (15.2%). The analysis also identified mutations in rarely mutated genes U2AF1, SF3B1, EZH2 and SETBP1 in 4/231 (1.7%), 4/231 (1.7%), 1/231 (0.4%) and 1/231 (0.4%) samples, respectively.
Figure: Distribution of gene mutations with VAF ≥ 2% in AML cohort. Each column represents one patient (n = 231). Each row represents one gene described on left, on the right is shown the number of patients with mutation in the gene and its percentage from the total cohort. The color of the squares represents the status of the gene: red – single mutated, blue – double mutated, black – triple mutated, white/grey – no mutation.
Conclusion
The results of mutational analysis of large cohort of AML patients show high heterogeneity of detected mutations. Surprisingly we have detected high percentage of patients with mutations in gene NRAS. Together with sequencing results from the time of remission/relapse/resistance of the disease, the data will enable to get more complex view on the development of AML in time.
Supported by Ministry of Health of the Czech Republic, grant nr. 15-25809A, and by project MUNI/A/1106/2016. All rights reserved.
Session topic: 3. Acute myeloid leukemia - Biology
Keyword(s): mutation analysis, AML
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