TET2 mutations in acute myeloid leukemia (AML): results from a comprehensive genetic and clinical analysis of the AML study group.

Purpose: The tet oncogene family member 2 (TET2) gene was recently identified to be mutated in myeloid disorders including acute myeloid leukemia (AML). To date, there is increasing evidence for a functional role of TET2 mutations (TET2(mut)) in AML. Thus, we explored the frequency, gene-expression pattern, and clinical impact of TET2(mut) in a large cohort of patients with AML in the context of other AML-associated aberrations.

TP53 alterations in acute myeloid leukemia with complex karyotype correlate with specific copy number alterations, monosomal karyotype, and dismal outcome.

To assess the frequency of TP53 alterations and their correlation with other genetic changes and outcome in acute myeloid leukemia with complex karyotype (CK-AML), we performed integrative analysis using TP53 mutational screening and array-based genomic profiling in 234 CK-AMLs. TP53 mutations were found in 141 of 234 (60%) and TP53 losses were identified in 94 of 234 (40%) CK-AMLs; in total, 164 of 234 (70%) cases had TP53 alterations. TP53-altered CK-AML were characterized by a higher degree of genomic complexity (aberrations per case, 14.

Monitoring of minimal residual disease in NPM1-mutated acute myeloid leukemia: a study from the German-Austrian acute myeloid leukemia study group.

Purpose: To evaluate the prognostic value of minimal residual disease (MRD) in patients with acute myeloid leukemia (AML) with NPM1 mutation (NPM1(mut)).

Patients And Method: RNA-based real-time quantitative polymerase chain reaction (RQ-PCR) specific for the detection of six different NPM1(mut) types was applied to 1,682 samples (bone marrow, n = 1,272; blood, n = 410) serially obtained from 245 intensively treated younger adult patients who were 16 to 60 years old.

Results: NPM1(mut) transcript levels as a continuous variable were significantly associated with prognosis after each treatment cycle.

IDH1 and IDH2 mutations are frequent genetic alterations in acute myeloid leukemia and confer adverse prognosis in cytogenetically normal acute myeloid leukemia with NPM1 mutation without FLT3 internal tandem duplication.

Purpose: To analyze the frequency and prognostic impact of isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2) mutations in acute myeloid leukemia (AML).

Patients And Methods: We studied 805 adults (age range, 16 to 60 years) with AML enrolled on German-Austrian AML Study Group (AMLSG) treatment trials AML HD98A and APL HD95 for mutations in exon 4 of IDH1 and IDH2. Patients were also studied for NPM1, FLT3, MLL, and CEBPA mutations.

High-resolution single-nucleotide polymorphism array-profiling in myeloproliferative neoplasms identifies novel genomic aberrations.

Single-nucleotide polymorphism arrays allow for genome-wide profiling of copy-number alterations and copy-neutral runs of homozygosity at high resolution. To identify novel genetic lesions in myeloproliferative neoplasms, a large series of 151 clinically well characterized patients was analyzed in our study. Copy-number alterations were rare in essential thrombocythemia and polycythemia vera.

Gene mutations and response to treatment with all-trans retinoic acid in elderly patients with acute myeloid leukemia. Results from the AMLSG Trial AML HD98B.

Background: In a previous randomized trial, AML HD98B, we showed that administration of all-trans retinoic acid in addition to intensive chemotherapy improved the outcome of older patients with acute myeloid leukemia. The objectives of this study were to evaluate the prognostic impact of gene mutations and to identify predictive genetic factors for the all-trans retinoic acid treatment effect.

Design And Methods: Data from mutation analyses of the NPM1, CEBPA, FLT3, and MLL genes were correlated with outcome in patients 61 years and older treated within the AML HD98B trial.

Mutations and treatment outcome in cytogenetically normal acute myeloid leukemia.

Background: Mutations occur in several genes in cytogenetically normal acute myeloid leukemia (AML) cells: the nucleophosmin gene (NPM1), the fms-related tyrosine kinase 3 gene (FLT3), the CCAAT/enhancer binding protein alpha gene (CEPBA), the myeloid-lymphoid or mixed-lineage leukemia gene (MLL), and the neuroblastoma RAS viral oncogene homolog (NRAS). We evaluated the associations of these mutations with clinical outcomes in patients.

Methods: We compared the mutational status of the NPM1, FLT3, CEBPA, MLL, and NRAS genes in leukemia cells with the clinical outcome in 872 adults younger than 60 years of age with cytogenetically normal AML.

Mutant nucleophosmin (NPM1) predicts favorable prognosis in younger adults with acute myeloid leukemia and normal cytogenetics: interaction with other gene mutations.

To assess the prognostic relevance of mutations in the NPM1 gene encoding a nucleocytoplasmic shuttle protein in younger adults with acute myeloid leukemia (AML) and normal cytogenetics, sequencing of NPM1 exon 12 was performed in diagnostic samples from 300 patients entered into 2 consecutive multicenter trials of the AML Study Group (AMLSG). Treatment included intensive double-induction therapy and consolidation therapy with high cumulative doses of high-dose cytarabine. NPM1 mutations were identified in 48% of the patients including 12 novel sequence variants, all leading to a frameshift in the C-terminus of the nucleophosmin 1 (NPM1) protein.