DNMT3A、FLT3-ITD合并NPM1基因突变正常核型急性髓系白血病患者的临床特征及预后分析

目的 分析DNMT3A、FLT3-ITD合并NPM1基因突变的正常核型急性髓系白血病(AML)患者的临床特征,探讨该类患者的预后.方法 回顾性分析2005年12月至2014年6月就诊的109例正常核型AML患者的临床特征及预后.其中DNMT3A/FLT3-ITD/NPM1+AML患者共25例,单独FLT3-ITD+ AML患者共32例,单独NPM1+AML患者24例,单独DNMT3A+ AML患者28例.结果 25例DNMT3A/FLT3-ITD/NPM1+ AML患者平均年龄46岁,伴有高白细胞(81.7×109/L)及较高的骨髓原始细胞(66.3％).其中,17例选择大剂量化疗,8例行异基因造血干细胞移植,与DNMT3A+、FLT3-ITD+、NPM1+AML组比较,差异均无统计学意义.25例DNMT3A/FLT3-ITD/NPM1+患者的3年总生存率为17.65％,3年无病生存率为13.88％,与DNMT3A+、FLT3-ITD+、NPM1+AML组差异均有统计学意义(P值分别为0.049 9、0.036 1、0.013 4),3年无病生存率差异无统计学意义(均P＞ 0.05).结论 DNMT3A、FLT3-ITD合并NPM1基因突变的正常AML患者往往合并高的外周血白细胞及骨髓原始细胞,预后较差.     

FLT3-ITD,NPM1, and DNMT3A Gene Mutations and Risk Factors in Normal Karyotype Acute Myeloid Leukemia and Myelodysplastic Syndrome Patients in Upper Northern Thailand

Objective: Approximately 40-45% of AML and MDS patients have a cytogenetically normal karyotype (CN-AML and CN-MDS). The frequency and types of gene mutations in these cases may differ among various populations. The objective of this study was to identify frequencies and types of FLT3-ITD, NPM1, and DNMT3A mutations, and associations of them with clinical data and risk factors in CN-AML and CN-MDS cases in upper Northern Thailand. Methods: Bone marrow samples of 40 CN-AML and 60 CN-MDS patients were analyzed for gene mutations by direct sequencing. In addition, data for potential risk factors were obtained for comparison. Results: Frequencies of FLT3-ITD, NPM1, and DNMT3A mutations were 25.0%, 17.5%, and 10.0%, respectively in CN-AML, but all zero in CN-MDS cases. NPM1 mutations were found at a median age older than the wild type (58 vs 47 years) while DNMT3A mutations were associated with an increase in the white blood cell count. In all patients, factors for the mutations of these three genes included age ≤ 60 years, and a history of hypertension. Conclusion: When considering mutations in only normal karyotype patients, the frequency of FLT3-ITD, NPM1, DNMT3A mutations in CN-AML patients in upper Northern Thailand were found to occur at lower rates than in Western patients and to differ from other Asian populations including parts of Thailand. No mutations were observed in CN-MDS cases. Some types of gene mutations differed from previous studies, possibly attributable to differences in geography, lifestyle and genetic backgrounds. Links with age ≤ 60 years and history of hypertension were found. Investigation of these three genes in an intermediate risk group with a normal karyotype is useful for a better understanding of molecular leukemogenetic steps in CN-AML and CN-MDS patients and may be beneficial for planning treatment and prevention in the population of upper Northern Thailand.     

Landscape of TET2 mutations in acute myeloid leukemia

We investigated ten-eleven translocation 2 (TET2) mutations in acute myeloid leukemia (AML), their correlation with other gene mutations and prognostic value. By deep-sequencing, 131 somatic TET2 mutations were identified in 87/318 (27.4%) patients. Of 87 mutated cases, 44 (50.6%) carried two mutations. TET2 mutations were concomitantly observed with mutations in NPM1, FLT3-ITD, FLT3-TKD, JAK2, RUNX1, CEBPA, CBL and KRAS. However, TET2 mutations rarely concomitantly occurred with IDH1mut or IDH2mut (2/251 or 0/184; P=0.046 and P=0.003, respectively). TET2 mutations were associated with normal karyotype AML (CN-AML) (62/206 (30.1%) CN-AML vs 20/107 (18.7%) aberrant karyotype; P=0.031), higher white blood cell count (mean 65.3 vs 40.3 × 10(9)/l, P=0.023), lower platelet count (mean 68.6 vs 92.4 × 10(9)/l, P=0.03) and higher age (67.5 vs 65.2 years, P<0.001). Survival analyses were restricted to de novo CN-AML patients (n=165) and showed inferior event-free survival (EFS) of TET2 mutations compared with TET2wt (median: 6.7 vs 18.7 months, P=0.009). This negative effect of TET2 mutation on EFS was particularly observed in patients 65 years (median: 8.9 months vs not reached (n.r.), P=0.027) as well as in patients of the European LeukemiaNet favorable-risk subgroup, that is, patients harboring mutated CEBPA and/or mutated NPM1 without FLT3-ITD (median: 10.3 vs 41.3 months, P=0.048). These data support a role for TET2 as an important prognostic biomarker in AML.     

Role of genotype-based approach in the clinical management of adult acute myeloid leukemia with normal cytogenetics

Acute myeloid leukemia (AML) is the most common form of acute leukemia affecting adults. Although it is a complex disease driven by numerous genetic and epigenetic abnormalities, nearly 50% of patients exhibit a normal karyotype (CN-AML) with an intermediate cytogenetic risk. However, a widespread genomic analysis has recently shown the recurrence of genomic aberrations in this category (mutations of FLT3, CEBPA, NPM1, RUNX1, TET2, IDH1/2, DNMT3A, ASXL1, MLL and WT1) thus revealing its marked genomic heterogeneity. In this perspective, a global gene expression analysis of AML patients provides an independent prognostic marker to categorize each patient into clinic-pathologic subgroups based on its molecular genetic defects. Consistently such classification, taking into account the uniqueness of each AML patient, furnishes an individualized treatment approach leading a step closer to personalized medicine. Overall the genome-wide analysis of AML patients, by providing novel insights into biology of this tumor, furnishes accurate prognostic markers as well as useful tools for selecting the most appropriate treatment option. Moreover it provides novel therapeutic targets useful to enhance efficacy of the current anti-AML therapeutics. Here we describe the prognostic relevance of such new genetic data and discuss how this approach can be used to improve survival and treatment of AML patients.     

Clinical Effect of Combined Mutations in DNMT3A,FLT3-ITD,and NPM1 Among Egyptian Acute Myeloid Leukemia Patients

BackgroundGenotypic mutation of fms like tyrosine kinase 3 (FLT3), Nucleophosmin (NPM1), and DNA-methyltransferase 3A (DNMT3A) has been involved in the leukemogenesis of acute myeloid leukemia (AML), with the well known poor prognostic role of FLT3 and DNMT3A and favorable role for the NPM1 mutation.Patients and MethodsA total of 123 patients with AML treated at the National Cancer Institute, Cairo University were examined for mutations in DNMT3A, FLT3, and NPM1 using polymerase chain reaction (PCR) for detecting FLT3 internal tandem duplication (ITD) and allele-specific PCR to detect DNMT3A and NPM1A mutations. Two-way direct sequencing and Gene Mapper version 4.0 software (Fred Hutchinson Cancer Research Center) sequencing were used as confirmatory tests for DNMT3A and NPM1A mutations, respectively.ResultsDNMT3A, FLT3-ITD, and NPM1A gene mutations were detected in 22 (17.9%), 22 (17.9%), and 24 (19.5%) patients, respectively. DNMT3A/FLT3, NPM1A/FLT3, and DNMT3A/NPM1A combined mutant genotypes were detected in 5 (4.1%), 9 (7.3%), and 3 (2.4%) patients, respectively. Two patients (1.6%) had triple mutant genotypes (DNMT3A/FLT3/NPM1A). FLT3 and DNMT3A mutations had a significant negative effect on complete response (CR) rates (P = .016). FLT3-ITD mutation was significantly associated with older age (P = .029), and lower overall survival (OS) rates (P = .046). DNMT3A/FLT3 combined mutant genotypes were significantly associated with a lower OS rate (P = .016). Mutant NPM1/wild type FLT3, wild type DNMT3A/FLT3, and mutant NPM1A/wild type DNMT3A combinations were significantly associated with higher CR rates (P = .006, P = .006, and P = .023, respectively).ConclusionDNMT3A, FLT3-ITD, and NPM1A are frequent mutations in Egyptian AML. FLT3-ITD mutations are frequent in older patients. DNMT3A and FLT3-ITD mutations were associated with an unfavorable prognosis, but the NPM1A mutation has tendency to indicate a good prognosis.     

Prognostic implication of gene mutations on overall survival in the adult acute myeloid leukemia patients receiving or not receiving allogeneic hematopoietic stem cell transplantations

Several gene mutations have been shown to provide clinical implications in patients with acute myeloid leukemia (AML). However, the prognostic impact of gene mutations in the context of allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains unclear. We retrospectively evaluated the clinical implications of 8 gene mutations in 325 adult AML patients; 100 of them received allo-HSCT and 225 did not. The genetic alterations analyzed included NPM1, FLT3-ITD, FLT3-TKD, CEBPA, RUNX1, RAS, MLL-PTD, and WT1. In patients who did not receive allo-HSCT, older age, higher WBC count, higher lactate dehydrogenase level, unfavorable karyotype, and RUNX1 mutation were significantly associated with poor overall survival (OS), while CEBPA double mutation (CEBPA^double-mut) and NPM1^mut/FLT3-ITD^neg were associated with good outcome. However, in patients who received allo-HSCT, only refractory disease status at the time of HSCT and unfavorable karyotype were independent poor prognostic factors. Surprisingly, RUNX1 mutation was an independent good prognostic factor for OS in multivariate analysis. The prognostic impact of FLT3-ITD or NPM1^mut/FLT3-ITD^neg was lost in this group of patients receiving allo-HSCT, while CEBPA^double-mut showed a trend to be a good prognostic factor. In conclusion, allo-HSCT can ameliorate the unfavorable influence of some poor-risk gene mutations in AML patients. Unexpectedly, the RUNX1 mutation showed a favorable prognostic impact in the context of allo-HSCT. These results need to be confirmed by further studies with more AML patients.     

Prognostic Impact of Concurrent DNMT3A,FLT3 and NPM1 Gene Mutations in Acute Myeloid Leukemia Patients

BackgroundAcute myeloid leukemia (AML) is one of the rapidly progressing malignancies which is characterized by unregulated proliferation of hematopoietic precursors. Technological improvements enhanced the availability of genetic AML biomarkers. The clinical relevance of these molecular markers for AML diagnosis, planning of therapy and risk stratification are increasing evidently.MethodsIn current study, one hundred newly diagnosed AML patients before receiving induction chemotherapy were included, they were subjected to clinical examination, cytochemical and morphological analysis of blood cells, flow cytometric, cytogenetic and molecular genetic analysis for detection of NPM1, FLT3-ITD and DNMT3A mutations. Direct sequencing analysis for detection of NPM1 and DNMT3A genes mutations were done. FLT3 /ITD gene mutation was detected by gel electrophoresis after PCR amplification.ResultsAccording to genetic markers, our AML patients are classified in to further 8groups. AML patients with three DNMT3A/FLT3/NPM1 gene mutations (AML ^{DNMT3A /FLT3/NPM1}) this group of patients presented with a heavy disease burden, had an elevated WBC in comparison to other groups (70 vs. 41 × 10³/μL; P = .019), and BM blast counts (71% vs. 55.6%, P < .02). When comparing eight groups for death event there were significant difference among groups; P = .005, group 1 (AML ^{DNMT3A /FLT3/NPM1}) showed rapid decline of the cumulative overall survival. There was a significant difference among 8 groups as regards response to treatment after 14 days (P = .02), group 7 AML with (DNMT3A +NMP1) gene mutations showed better response to treatment (100%), groups 1 and 3 AML with (NPM1+DNMT3A +NMP1) gene mutations and AML with isolated FLT3-ITD showed no response to treatment after 14 days. And as regards response to treatment after 28 days, the eight groups showed no significant difference (P = .14).ConclusionOur study supports adverse prognostic effect of presence of DNMT3A gene mutation either alone or in the presence of FLT3 and/or NPM1 gene mutations.     

Detection of CD34, TdT, CD56, CD2, CD4, and CD14 by flow cytometry is associated with NPM1 and FLT3 mutation status in cytogenetically normal acute myeloid leukemia

MethodsWe retrospectively correlated NPM1 and FLT3 mutation status with flow cytometric profile of leukemic blasts in 83 adult patients with cytogenetically normal acute myeloid leukemia (CN-AML).ResultsMutation of the NPM1 gene (NPM1.mt) was found in 39 (47%) of 83 patients, and internal tandem duplication (ITD) of the FLT3 gene (FLT3-ITD) was seen in 38 (46%) of 83 patients. Patients with CN-AML and with NPM1.mt were less likely to express CD34 (33% vs. 93%; 2P = .0001), CD2 (0% vs. 14%; 2P = .0187), and CD14 (6% vs. 22%, 2P = .0476), and were more likely to express CD4 (65.5% vs. 37%; 2P = .0367) and CD19 (49% vs. 27%; 2P = .0506). The patients with CN-AML and with FLT3-ITD were more likely to express CD56 (47% vs. 23%; 2P = .0393). Moreover, patients with favorable prognostic combination of NPM1.mt and wild-type (wt) FLT3 (n = 18) were less likely to express CD34 (33% vs. 74% all others; 2P = .0021) and CD56 (6% vs. 37% all others; 2P = .0072). The group with an unfavorable prognostic combination of NPM1-wt and FLT3-ITD (n = 17) were more likely to express CD34 (88% vs. 45% all others; 2P = .0011) and TdT (40% vs. 2% all others; 2P = .0054).ConclusionsIn patients with CN-AML, characteristic flow cytometric profile is associated with NPM1 and FLT3 mutation status.     

Role of ASXL1 and TP53 mutations in the molecular classification and prognosis of acute myeloid leukemias with myelodysplasia-related changes

Acute myeloid leukemias (AML) with myelodysplasia-related changes (AML-MRC) are defined by the presence of multilineage dysplasia (MLD), and/or myelodysplastic syndrome (MDS)-related cytogenetics, and/or previous MDS. The goal of this study was to identify distinct biological and prognostic subgroups based on mutations of ASXL1, RUNX1, DNMT3A, NPM1, FLT3 and TP53 in 125 AML-MRC patients according to the presence of MLD, cytogenetics and outcome. ASXL1 mutations (n=26, 21%) were associated with a higher proportion of marrow dysgranulopoiesis (mutant vs. wild-type: 75% vs. 55%, p=0.030) and were mostly found in intermediate cytogenetic AML (23/26) in which they predicted inferior 2-year overall survival (OS, mutant vs. wild-type: 14% vs. 37%, p=0.030). TP53 mutations (n=28, 22%) were mostly found in complex karyotype AML (26/28) and predicted poor outcome within unfavorable cytogenetic risk AML (mutant vs. wild-type: 9% vs. 40%, p=0.040). In multivariate analysis, the presence of either ASXL1 or TP53 mutation was the only independent factor associated with shorter OS (HR, 95%CI: 2.53, 1.40-4.60, p=0.002) while MLD, MDS-related cytogenetics and previous MDS history did not influence OS. We conclude that ASXL1 and TP53 mutations identify two molecular subgroups among AML-MRCs, with specific poor prognosis. This could be useful for future diagnostic and prognostic classifications.     

Clinical Implication of DNMT3A and TET2 Genes Mutations in Cytogenetically Normal Acute Myeloid Leukemia

Background: Refining risk stratification of cytogenetically  normal AML (CN-AML) cases is important for decision making and tailoring of therapy. In this context genetic and epigenetic mutations was considered. Among these epigenetic regulators are DNMT3A & TET2 genes. Therefore, the aim of  this study was to determine the prevalence of DNMT3A and TET2 genes mutations and their impact on the outcome of  adult AML patients. Subjects and methods: The present study is cross sectional study which was conducted on 39 adult CN-AML patients at diagnosis. For all included patients sanger sequencing was done for DNMT3A exon 23 and TET2 exon 3 genes. Results: DNMT3A mutations were detected in 8 of 39 patients (20.5%), and in 5 of 39 patients(12.8%) in TET gene. Two CN-AML  patients had combined mutations in both genes. All of the mutations detected were missense and only one was frame shift. Mutated TET2 or DNMT3A genes were significantly associated with failure of complete remission (CR) (p <0.001), higher mortality rate, shorter OS (mean=16 versus 22.7 months) and shorter DFS (mean= 9.5 versus 21.4 months) when compared to non-mutated ones. Conclusion: Mutated TET2 and DNMT3A detection define a subgroup of CN-AML patients with poor outcome.     

Outcome of older adults with cytogenetically normal AML (CN-AML) and FLT3 mutations

AML patients under the age of 60 whose blasts harbor a FLT3 internal tandem duplication (ITD) mutation have a higher relapse rate and inferior survival compared to those without this mutation. To determine if FLT3ITD also carries a negative prognostic impact in older adults receiving therapies commonly used in this age group, we retrospectively analyzed outcomes of patients ≥60 years with CN-AML according to FLT3 mutation status. We identified 91 newly diagnosed CN-AML patients, 55 with wild-type FLT3 and 36 with FLT3ITD. Of the 91 patients, 36 received supportive care and/or experimental therapies while the remaining 55 received induction chemotherapy, followed by allogeneic SCT in 17 of these patients. Based on univariate analysis, advanced age at diagnosis was significantly associated with shorter overall survival (OS) (p < .0001) while intensive therapies were associated with improved OS (p < .0001). In a multivariate analysis that accounted for type of treatment, patient age, gender, and WBC count, FLT3ITD was significantly associated with shorter OS compared to wtFLT3 [p = .001; hazard ratio (HR) = 2.23; 95% CI: 1.35-3.70]. Our data support the negative prognostic impact of FLT3ITD in older adults with CN-AML.     

Sex disparity in acute myeloid leukaemia with FLT3 internal tandem duplication mutations: implications for prognosis

Incidence, molecular presentation and outcome of acute myeloid leukaemia (AML) are influenced by sex, but little attention has been directed at untangling sex‐related molecular and phenotypic differences between female and male patients. While increased incidence and poor risk are generally associated with a male phenotype, the poor prognostic FLT3 internal tandem duplication (FLT3‐ITD) mutation and co‐mutations with NPM1 and DNMT3A are overrepresented in female AML. Here, we have investigated the relationship between sex and FLT3‐ITD mutation status by comparing clinical data, mutational profiles, gene expression and ex vivo drug sensitivity in four cohorts: Beat AML, LAML‐TCGA and two independent HOVON/SAKK cohorts, comprising 1755 AML patients in total. We found prevalent sex‐associated molecular differences. Co‐occurrence of FLT3‐ITD, NPM1 and DNMT3A mutations was overrepresented in females, while males with FLT3‐ITDs were characterized by additional mutations in RNA splicing and epigenetic modifier genes. We observed diverging expression of multiple leukaemia‐associated genes as well as discrepant ex vivo drug responses, suggestive of discrete functional properties. Importantly, significant prognostication was observed only in female FLT3‐ITD‐mutated AML. Thus, we suggest optimization of FLT3‐ITD mutation status as a clinical tool in a sex‐adjusted manner and hypothesize that prognostication, prediction and development of therapeutic strategies in AML could be improved by including sex‐specific considerations.     

TET2合并DNMT3A突变及其他共存基因突变对急性髓系白血病患者预后的影响

  目的  探究TET2合并DNMT3A突变及其他共存基因突变对成人非M3型急性髓系白血病（acute myeloid leukemia,AML）患者预后的影响。  方法  回顾性分析2018年1月至2021年9月于南昌大学第一附属医院确诊的初治且行血液肿瘤相关突变基因外显子二代测序检测的512例成人 AML（非 M3 型）患者的临床资料,分析患者的临床特征、疗效及生存情况。  结果  本研究共纳入110例AML患者,TET2突变组64例,DNMT3A单突变组46例。男性50例（45.5%）,中位年龄54（15～79）岁。TET2基因突变频率为12.5%（64/512）,98.4%（63/64）患者突变基因数≥2个,每例患者平均合并5.2个突变基因。NPM1（43.8%）、DNMT3A（42.2%）、FLT3-ITD/TKD（40.6%）、CEBPA（26.6%）、TTN（20.3%）为TET2突变常见的共存突变基因。TET2合并DNMT3A突变患者初次诱导完全缓解（complete response,CR）率为46.2%,略低于TET2单突变患者的76.9%（P=0.077）,与DNMT3A单突变患者无显著性差异（P=0.952）。TET2合并DNMT3A突变患者的中位总生存（median overall survival,mOS）时间为9.5个月,明显低于TET2单突变患者（P=0.002）,而与DNMT3A单突变患者无显著性差异（P=0.414）。三者的中位无复发生存（median relapse- free survival,mRFS）时间无显著性差异（P>0.05）。在TET2突变背景下,合并K/NRAS突变患者的CR率为28.6%,明显低于无K/NRAS突变患者的75.0%（P=0.030）,合并FLT3-ITD突变患者的mOS明显短于无FLT3-ITD突变患者（P=0.030）。多因素分析显示年龄≥60岁、合并FLT3-ITD突变、初次诱导未达CR是影响TET2突变AML患者总生存时间（overall survival,OS）的独立危险因素,DNMT3A突变不影响TET2突变患者OS。  结论  TET2突变是AML患者常见突变,且常合并共存基因突变。共存基因突变与TET2突变共同影响AML患者预后。基于二代测序的基因突变检测对指导AML精确分层及精准治疗具有重要意义。      

A novel prognostic scoring model for newly diagnosed FLT3-ITD-positive acute myeloid leukemia

FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) is one of the most common somatic mutations in acute myeloid leukemia (AML). However, the molecular structure characteristics and widely accepted prognostic factors for FLT3-ITD are still not well described. This study aimed to retrospectively examine 81 patients with FLT3-ITD-positive AML diagnosed and treated at the First Affiliated Hospital of Zhejiang University from December 2013 to March 2018 using the next-generation sequencing 185-gene platform. High variant allele frequency (VAF) [> 0.48, P = 0.0089 for overall survival (OS), P = 0.13 for relapse-free survival (RFS)], multiple ITDs (> 1 ITDs, P = 0.011 for OS, P = 0.033 for RFS) and longer insertion length (> 69 bp, P = 0.14 for OS, P = 0.0078 for RFS) predicted poor survival. The study further proposed an easily applicable scoring model for OS using the Least Absolute Shrinkage and Selector Operation (LASSO) Cox regression model. Also, an independent cohort of 30 patients was used for external model validation. The mode was expressed as follows: 0.659 × FLT3-ITD VAF + 0.375 × FLT3-ITD number + 0.807 × Age + 0.688 × DNMT3A + 1.939 × U2AF1 (FLT3-ITD VAF > 0.48 scored 1; FLT3-ITD number scored 1 if carried 1 ITD, 2 if carried ≥ 2 ITDs; age > 44 years scored 1, the presence of DNMT3A or U2AF1 scored 1; 0 for other conditions). It categorized patients into low-risk (L-R, score < 1, n = 20) and high-risk (H-R, score ≥ 1, n = 61) groups based on the risk score with a significant difference in survival (3-year OS, P < 0.0001; 3-year RFS, P = 0.0005). A prognostic nomogram that integrated these five factors was developed with a concordance index calculation [OS: 0.68, 95% CI (0.64-0.72)].     

IDH1/2 but not DNMT3A mutations are suitable targets for minimal residual disease monitoring in acute myeloid leukemia patients: a study by the Acute Leukemia French Association

Acute myeloid leukemia (AML) is a heterogeneous disease. Even within the same NPM1-mutated genetic subgroup, some patients harbor additional mutations in FLT3, IDH1/2, DNMT3A or TET2. Recent studies have shown the prognostic significance of minimal residual disease (MRD) in AML but it remains to be determined which molecular markers are the most suitable for MRD monitoring. Recent advances in next-generation sequencing (NGS) have provided the opportunity to use multiple molecular markers. In this study, we used NGS technology to assess MRD in 31 AML patients enrolled in the ALFA-0701 trial and harboring NPM1 mutations associated to IDH1/2 or DNMT3A mutations. NPM1 mutation-based MRD monitoring was performed by RTqPCR. IDH1/2 and DNMT3A mutations were quantified by NGS using an Ion Torrent Proton instrument with high coverage (2 million reads per sample). The monitoringof IDH1/2 mutations showed that these mutations were reliable MRD markers that allowed the prediction of relapse in the majority of patients. Moreover, IDH1/2 mutation status predicted relapse or disease evolution in 100% of cases if we included the patient who developed myelodysplastic syndrome. In contrast, DNMT3A mutations were not correlated to the disease status, as we found that a preleukemic clone with DNMT3A mutation persisted in 40% of the patients who were in complete remission, reflecting the persistence of clonal hematopoiesis.     

Prognostic significance of FLT3 internal tandem repeat in patients with de novo acute myeloid leukemia treated with reinforced courses of chemotherapy.

FLT3 internal tandem duplications (FLT3-ITDs) are present in nearly 25% of patients with AML and have been associated with poor response to conventional therapy and poor outcome. We retrospectively evaluated the effect of reinforced courses of chemotherapy on the prognostic value of FLT3-ITDs in 159 AML patients prospectively enrolled in the ALFA-9000 trial, which randomly compared three reinforced induction regimens (standard 3+7 including high-dose daunorubicin, double induction, and timed-sequential therapy). FLT3-ITD was present in 40/159 (25%) blast samples and associated with high WBC (P = 0.002) and cytogenetics (P < 0.001) with a higher incidence (35%) in patients with a normal karyotype. There was no difference in CR rate between FLT3-wt and FLT3-ITD patients (80% vs 78%). Relapse-free survival (RFS) was similar in both groups (5-year RFS, 33% vs 32%; P = 0.41), even after adjustment for age, sex, WBC, cytogenetics, and treatment arm. A trend to a worse survival was observed in the FLT3-ITD group (estimated 5-year OS, 23% vs 37%; P = 0.09), mainly in patients with a normal karyotype. This was associated with a dramatic outcome in relapsing FLT3-ITD patients (estimated 3-year post-relapse survival, 0% vs 27%; P = 0.04). These results suggest that the bad prognosis associated with FLT3-ITDs in AML might be partly overcome using reinforced chemotherapy. Early detection of FLT3 mutations might thus be useful to intensify induction as well as post-remission therapy in FLT3-ITD patients.     

Revealing very small FLT3 ITD mutated clones by ultra-deep sequencing analysis has important clinical implications in AML patients

FLT3 internal tandem duplication (ITD), one of the most frequent mutations in Acute Myeloid Leukemia (AML), is reported to be an unstable marker, as it can evolve from FLT3 ITD- to ITD+ during the disease course. A single-gene sensitive mutational screening approach may be helpful for better clarifying the exact timing of mutation occurrence, especially when FLT3 ITD appears to occur late, at disease progression. We developed an amplicon-based ultra-deep-sequencing (UDS) approach for FLT3 mutational screening. We exploited this highly sensitive technology for the retrospective screening of diagnosis, relapse and follow-up samples of 5 out of 256 cytogenetically normal (CN-) AML who were FLT3 wild-type at presentation, but tested ITD+ at relapse or disease progression. Our study revealed that all patients carried a small ITD+ clone at diagnosis, which was undetectable by routine analysis (0,2–2% abundance). The dynamics of ITD+ clones from diagnosis to disease progression, assessed by UDS, reflected clonal evolution under treatment pressure. UDS appears as a valuable tool for FLT3 mutational screening and for the assessment of minimal residual disease (MRD) during follow-up, by detecting small ITD+ clones that may survive chemotherapy, evolve over time and definitely worsen the prognosis of CN-AML patients.     

老年正常核型急性髓系白血病患者临床特征及预后分析

目的 探讨老年正常核型急性髓系白血病(CN-AML)患者的临床特征及其预后相关因素.方法 回顾性分析104例初治老年CN-AML(M3除外)患者的临床资料.用χ2检验分析完全缓解(CR)的影响因素.用Kaplan-Meier法进行生存分析,并采用Log-rank检验对预后相关影响因素进行单因素分析,采用Cox回归模型进行多因素分析.结果 104例患者中首次化疗后可评价疗效者72例,CR率为38.9%(28/72),总有效率为55.6%(40/72).白细胞计数(WBC)<100×109/L、NPM1突变阳性患者的CR率较高[59.4%(38/64)比12.5%(1/8),83.3%(10/12)比36.4%(8/22),均P<0.05].104例患者中位总生存(OS)时间为6.9个月.单因素分析显示年龄≥70岁、继发AML、高WBC(≥100×109/L)、FLT3-内部串联重复(ITD)突变阳性、CD7阳性、达CR诱导疗程数>2个以及Charlson合并疾病指数(CCI)评分≥2分的患者OS时间较短(均P<0.05).多因素分析显示FLT3-ITD突变阳性(HR=7.61,95%CI 1.80~32.11,P=0.006)及达CR诱导疗程数>2个(HR=10.11,95%CI 2.38~43.03,P=0.002)是患者OS的独立不良影响因素.结论 老年CN-AML患者的预后是多种因素综合作用的结果,FLT3-ITD突变阳性、 达CR诱导疗程数>2个是老年CN-AML患者不良OS的独立影响因素.