Incidence and clinical significance of FLT3 and nucleophosmin mutation in childhood acute myeloid leukemia in Chile

Abstract Introduction Acute myeloid leukemia (AML) is a heterogeneous disease and approximately one-third of its carriers do not have evident genetic abnormalities. The mutation of specific molecular markers, such as fms-like tyrosine kinase 3 (FTL3) internal tandem duplication (ITD), FLT3 tyrosine kinase domain (TKD) and nucleophosmin (NPM1), are associated with an adverse and favorable prognosis, respectively. Objective The objective was to determine the prevalence of FLT3/ITD and NPM1 in Chilean patients and their association with clinical data and prognosis. Method and Results Two hundred and thirty-two children were studied between 2011 and 2017, the median being 8.6 years (ranging from 1 to 18 months). Acute promyelocytic leukemia (APL) was diagnosed in 29%. The FLT3/ITD-mutated in non-promyelocytic AML was at 10% (14/133) and the FLT3/TKD, at 3.7% (2/54). In APL, it was at 25.4% (16/63). In non-promyelocytic AML, the FLT3/ITD-mutated was associated with a high leucocyte count, the median being 28.5 x mm3 (n= 14) versus 19.4 x mm3 (n= 119), (p= 0.25), in non-mutated cases. In APL, the median was 33.6 x mm3 (n= 15) versus 2.8 x mm3 (n= 47), (p < 0.001). The five-year overall survival (OS) in non-promyelocytic AML with non-mutated and mutated FLT3/ITD were 62.7% and 21.4%, respectively, (p < 0.001); the 5-year event-free survival (EFS) were 79.5% and 50%, respectively, (p < 0.01). The five-year OS in APL with non-mutated and mutated FLT3/ITD was 84.7% and 62.5%, respectively, (p= 0.05); the 5-year EFS was 84.7% and 68.8%, respectively, (p= 0.122). The NPM1 mutation was observed in 3.2% (5/155), all non-promyelocytic AML with the normal karyotype. Conclusion The FLT3/ITD mutation was observed more frequently in APL and associated with a higher white cell count at diagnosis. However, the most important finding was that the FLT3/ITD mutation was associated with a shorter survival in non-promyelocytic AML.

Effect of clonal hematopoiesis in remission on hematopoiesis recovery in patients with NPM1 mutated acute myeloid leukemia after chemotherapy / 中华血液学杂志

Objective: To investigate the effect of clonal hematopoiesis (CH) in remission on hematopoiesis recovery in patients with NPM1 mutated acute myeloid leukemia (AML) after chemotherapy. Methods: Retrospective analysis was performed on 86 patients with NPM1(mut) AML newly diagnosed and treated in the First Affiliated Hospital of Soochow University between July 2016 and June 2019. Their clinical data and NGS test results at diagnosis were analyzed. Moreover, bone marrow samples in remission were tested using Sanger sequencing. The log-rank test was used to analyze the difference in hematopoietic recovery, and Cox proportional hazard models were used to analyze the prognostic factors affecting hematopoietic recovery. Results: The median age of the 86 NPM1(mut) AML patients was 50 years (15-69 years). There were 39 males and 47 females. Forty-one patients were induced with intensity chemotherapy ("7 + 3"), whereas 45 patients were treated with low-dose cytarabine-based induction chemotherapy. At diagnosis, The most common mutations in the patients were FLT3, DNMT3A, TET2, and IDH1/IDH2 mutations. CH-associated mutations persisted in 21 patients during remission, and the mutations were DNMT3A, TET2, ASXL1, and IDH1/IDH2. The recovery time of neutrophils in patients with CH-associated mutations in remission was consistent with that in patients without CH in remission (P=0.282) but the recovery time of platelets in patients with CH in remission was significantly longer[26 (95% CI 21-32) days vs 25 (95% CI 23-26) days, P=0.032]. Furthermore, univariate analysis indicated that age, induced chemotherapy program, and CH in remission were risk factors for platelet recovery, whereas multivariate analysis indicated that induced chemotherapy program and CH in remission were independent risk factors for platelet recovery (HR=0.454, P=0.001 and HR=0.520, P=0.027, respectively) . Conclusion: CH in remission delays the hematopoietic recovery of patients with NPM1(mut) AML after chemotherapy.

Efficacy and Survival of Venetoclax Based Regimen in the Treatment of Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To explore the efficacy and survival of venetoclax based (VEN-based) regimen in the treatment of acute myeloid leukemia（AML）.@*METHODS@#A retrospective study was conducted in patients who received VEN-based regimen and completed at least 1 course of efficacy evaluation at the The First Affiliated Hospital of Nanchang University from July 2019 to July 2022. The incidence of complete remission （CR）/CR with incomplete hematologic recovery （CRi） rate, objective remission rate（ORR） and survival of patients with different risk strati- fication and gene subtypes were analyzed.@*RESULTS@#A total of 79 patients were enrolled, including 43 patients with newly diagnosed unfit AML （unfit AML） and 36 relapsed/refractory AML (R/R AML). The median age of the patients was 62(14-83) years old. 36 out of 79 patients achieved CR/CRi and the ORR of the whole cohort was 64.6%. The CR/CRi rate of unfit AML patients was significantly higher than that of R/R AML patients (60.5% vs 27.8%, P=0.004). In unfit AML cohort, the patients with NPM1 and IDH1/2 mutations were benefited, 8 out of 9 patients ahcieved CR/CRi, 7/8 and 5/8 patients achieved minimal residual disease (MRD) negativity, respectively. Six out of 9 patients with TET2 mutation achieved CR/CRi, 3/6 patients achieved MRD negativity. In R/R AML cohort, 2 out of 3 patients with RUNX1 mutation achieved CR/CRi, without MRD negative, while the CR/CRi rate of patients with other gene mutations was lower than 40%. The median follow-up time was 10.1(95%CI: 8.6-11.6) months. In whole cohort, the median overall survival (mOS) time was 9.1 months and the relapse free survival (RFS) time was not reached. The mOS and RFS of unfit AML patients were significantly longer than those of R/R AML patients (14.1 vs 6.8 months, P=0.013; not reached vs 3.3 months, P=0.000). In unfit AML cohort, the mOS of patients with NPM1 or IDH1/2 mutations was not reached, while that of patients without NPM1 or IDH1/2 mutations was 8.0 months (P=0.009; P=0.022). Furthermore, the mOS of patients with TP53 mutaion was significantly shorter than that of patients without TP53 mutation (5.2 vs 14.1 months， P=0.049). In R/R AML cohort, there was no significant difference in mOS between patients with mutation in each gene subtype and those without gene mutation (P>0.05). All patients had hematology adverse reactions, 91.1% patients had AE grade≥3. The most common non-hematology adverse reactions was infection, with an incidence of 91.1%. VEN-based regimen was tolerable for AML patients.@*CONCLUSION@#VEN-based regimen can achieve a high response rate, especially in unfit AML with acceptable safety, and some patients can achieve MRD negative. It is also effective in NPM1-, IDH1/2-positive patients with long survival time.

Efficacy of Venetoclax Plus Azacitidine in Relapsed/Refractory Acute Myeloid Leukemia Patients with FLT3-ITD Mutation / 中国实验血液学杂志

OBJECTIVE@#To explore the efficacy of venetoclax (VEN) plus azacitidine (AZA) in patients with FLT3-ITD mutated relapsed/refractory acute myeloid leukemia (FLT3-ITDmut R/R AML) and analyze the molecular genetic characteristics of the patients.@*METHODS@#Clinical baseline characteristics and follow-up data of 16 R/R AML patients treatd with VEN plus AZA in the hematology department of Shenzhen Second People's Hospital from November 2018 to April 2021 were collected. Leukemia related genes were detected by next-generation sequencing(NGS) or PCR. The relationship between the efficacy of VEN plus AZA and molecular genetics characteristics of patients with FLT3-ITDmut R/R AML were analyzed.@*RESULTS@#14.3% (1/7) of the patients in FLT3-ITDmut group and 22.2% (2/9) of the patients in FLT3-ITDwt group achieved complete remission (CR)/CR with incomplete blood count recovery (CRi), respectively, with no significant difference (P=0.69). There was no significant difference in overall response rate (ORR) (CR/CRi+PR) between FLT3-ITDmut group and FLT3-ITDwt group [42.9%(3/7) vs 44.4%(4/9), P=0.95], too. The median overall survival (OS) time of FLT3-ITDmut patients was significantly shorter than that of FLT3-ITDwt patients (130 vs 300 days, respectively) (P =0.02). Co-existing mutations of FLT3-ITD and IDH1 were detected in one patient who achieved CR. Co-existing mutations of FLT3-ITD and SF3B1 were found in one patient who achieved PR. Three FLT3-ITDmut R/R AML patients accompanied with NPM1 mutation had no response to VEN plus AZA.@*CONCLUSION@#VEN plus AZA showed a certain effect on patients with FLT3-ITDmut R/R AML. To improve OS of the patients, bridging transplantation is need. IDH1 and SF3B1 mutations might predict that patients with FLT3-ITDmut R/R AML have treatment response to VEN plus AZA, while the combination of NPM1 mutation may indicate poor response.

High-Throughput Sequencing Technology for Detection of Gene Mutations in Myeloid Malignancies and Its Clinical Prognostic Significance / 中国实验血液学杂志

OBJECTIVE@#To detect the gene mutations in patients with myeloid malignancies by high-throughput sequencing and explore the correlation between gene mutations and prognosis.@*METHODS@#A retrospective analysis was performed on 56 patients with myeloid malignancies who were hospitalized in the department of hematology, Peking University International Hospital from January 2020 to May 2021. The genetic mutations of the patients were detected by next-generation sequencing technology, and the correlation between the genetic mutations and prognosis of myeloid malignancies was analyzed.@*RESULTS@#In 56 patients, the number of mutated genes detected in a single patient is 0-9, with a median of 3. Sequencing results showed that the most common mutated genes were RUNX1(21.4%), TET2(17.9%), DNMT3A(17.9%), TP53(14.3%) and ASXL1(14.3%), among which the most common mutations occurred in the signaling pathway-related genes (23.3%) and the transcription factor genes (18.3%). 84% of the patients carried multiple mutated genes (≥2), and correlation analysis showed there were obvious co-occurring mutations between WT1 and FLT3, NPM1 and FLT3-ITD, and MYC and FLT3. TP53 mutation was more common in MDS patients.The overall survival time of patients with NRAS mutation was significantly shortened (P =0.049). The prognosis of patients with TP53 mutation was poor compared with those without TP53 mutation, but the difference wasn't statistically significant (P =0.08).@*CONCLUSION@#The application of next-generation sequencing technology is of great significance in myeloid malignancies, which is helpful to better understand the pathogenesis of the disease, to judge the prognosis and to find possible therapeutic targets.

Clinical Value of Translocator Protein Gene in Evaluating the Efficacy of FLT3-ITD/DNMT3A R882 Double-Mutated Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To observe the clinical significance of translocator proteins (TSPO) gene in the treatment of FLT3-ITD/DNMT3A R882 double-mutated acute myeloid leukemia (AML).@*METHODS@#Seventy-six patients with AML hospitalized in the Department of Hematology of the Affiliated People's Hospital of Ningbo University from June 2018 to June 2020 were selected, including 34 patients with FLT3-ITD mutation, 27 patients with DNMT3A R882 mutation, 15 patients with FLT3-ITD/DNMT3A R882 double mutation, as well as 19 patients with immune thrombocytopenia (ITP) hospitalized during the same period as control group. RNA was routinely extracted from 3 ml bone marrow retained during bone puncture, and TSPO gene expression was detected by transcriptome sequencing (using 2-deltadeltaCt calculation).@*RESULTS@#The expression of TSPO gene in FLT3-ITD group and DNMT3A R882 group at first diagnosis was 2.02±1.04 and 1.85±0.76, respectively, which were both higher than 1.00±0.06 in control group, but the differences were not statistically significant (P=0.671, P=0.821). The expression of TSPO gene in the FLT3-ITD/DNMT3A R882 group was 3.98±1.07, wich was significantly higher than that in the FLT3-ITD group and DNMT3A R882 group, the differences were statistically significant (P=0.032, P=0.021). The expression of TSPO gene in patients who achieved complete response after chemotherapy in the FLT3-ITD/DNMT3A R882 group was 1.19±0.87, which was significantly lower than that at first diagnosis, and the difference was statistically significant (P=0.011).@*CONCLUSION@#TSPO gene may be used as an indicator of efficacy in FLT3-ITD /DNMT3A R882 double-mutated AML.

Analysis of Gene Mutation Characteristics and Prognosis of Elderly Patients with Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To investigate the characteristics of gene mutation in elderly patients with acute myeloid leukemia (AML) and its effect on prognosis.@*METHODS@#The clinical and laboratorial characteristics of 54 AML patients (≥60 years old) in Department of Hematology, Tangdu Hospital were analyzed retrospectively during April 2016 to October 2019. Thirty-four AML/myelodysplastic syndrome/myeloproliferative neoplasm related mutant genes were detected by second-generation sequencing technology, and their clinical characteristics, treatment effect, and influence on prognosis were analyzed.@*RESULTS@#All the patients received DAC+CAG induction treatment, after 1-2 couses of treatment, 36 cases (66.7%) achieved complete response, with a total effective rate of 75.9%, and the median survival time was 17 months. The most frequent mutant genes were TET2 (33.3%), CEBPA (31.5%), DNMT3A (18.5%), ASXL1 (16.7%), NRAS (14.8%), RUNX1 (14.8%), FLT3-ITD (12.9%), TP53 (12.9%), NPM1 (12.9%), and IDH2 (12.9%). Among 7 patients with TP53 mutation, 6 cases obtained complete response after 1-2 courses of induction treatment, but there was no statistically significant difference in the effect on prognosis. Patients with FLT3-ITD and NRAS mutations had shorter overall survival time compared with who had no mutation (P=0.47, P=0.48). Multivariate analysis showed that FLT3-ITD and NRAS mutations were poor prognostic factors.@*CONCLUSION@#The incidence of TET2 gene mutation is high in elderly AML patients. AML patients with TET2 and TP53 mutations may benefit from Decitabine-based chemotherapy. However, patients with FLT3-ITD and NRAS mutations have a short survival time, and may have a poor prognosis.

Clinical Significance of Low Expression of LncRNA CASC15 in Acute Myeloid Leukemia with NPM1 Mutations / 中国实验血液学杂志

AbstractObjective: To identify the expression and methylation patterns of lncRNA CASC15 in bone marrow (BM) samples of acute myeloid leukemia (AML) patients, and further explore its clinical significance.@*METHODS@#Eighty-two de novo AML patients and 18 healthy donors were included in the study. Meanwhile, seven public datasets from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were included to confirm the expression and methylation data of CASC15. Receiver operating characteristic (ROC) curve analysis was applied to determine the discriminative capacity of CASC15 expression to identify AML. The patients were divided into CASC15high group and CASC15low group by X-tile method, and the prognostic value of CASC15 was identified by Kaplan-Meier method and univariate and multivariate Cox regression analysis.@*RESULTS@#The expression level of CASC15 was significantly decreased in BM cells of AML patients compared with healthy donors (P<0.001). ROC curve analysis suggested that CASC15 expression might be a potential biomarker to discriminate AML from controls. The expression of CASC15 was high at the early stage of hematopoiesis, and reached a peak at the stage of multipotent progenitors differentiation, then decreased rapidly, and was at a range of low level fluctuations in the subsequent process. Among FAB subtypes, CASC15 expression in M0 was significantly higher than that in M1-M7. Clinically, CASC15low patients were more likely to have NPM1 mutations than CASC15high patients (P=0.048), while CASC15high patients had a significantly higher frequency of IDH1 and RUNX1 mutations (P=0.021 and 0.014, respectively). Moreover, CASC15low group had a shorter overall survival (OS) in patients with NPM1 mutations. Furthermore, multivariate analysis confirmed that CASC15 expression was a significant independent risk factor for OS in NPM1 mutated AML patients. In addition, CASC15 methylation level in BM samples of AML patients was significantly decreased compared with healthy donors. Patients with CASC15 high methylation had poor OS and disease-free survival.@*CONCLUSION@#The expression of CASC15 is decreased in AML, and low CASC15 expression may predict adverse prognosis in AML patients with NPM1 mutations. Moreover, CASC15 methylation level in AML is significantly decreased, and high CASC15 methylation may predict poor prognosis in AML.

Detection of NPM1 Mutation in Acute Myeloid Leukemia by Droplet Digital PCR and Its Clinical Application Value / 中国实验血液学杂志

OBJECTIVE@#To establish the droplet digital PCR (ddPCR) assay for the detection of NPM1 type A mutation in patients with acute myeloid leukemia (AML), and to evaluate its specificity, sensitivity and its value in clinical application.@*METHODS@#NPM1 mutant and wildtype plasmids were used to verify the performance of ddPCR. Both ddPCR and Sanger sequencing were used to detect the bone marrow samples of 87 AML patients, which were confirmed by next generation sequencing (NGS). Moreover, NPM1 mutation burden was dynamically monitored in five patients by ddPCR.@*RESULTS@#The limit of blank (LOB) of ddPCR established for NPM1 mutation detection was 1.1 copies/μl, and the limit of detection (LOD) was 2.43 copies/μl, which had good linearity. Among the 87 newly diagnosed AML patients, ddPCR identified seventeen cases positive for NPM1 mutation (19.5%)， which was consistent with Sanger sequencing. NGS confirmed 12 positive cases, including 8 of type A mutations, 2 of type D mutations, and 2 of rare type mutations. The results of dynamic monitoring of NPM1 mutation burden in 5 patients showed that the NPM1 mutation burden decreased obviously even close to 0, when patients achieve complete remission after chemotherapy. However, the mutation burden was increased again at the time of relapse.@*CONCLUSION@#In this study, we established a ddPCR method for detection of NPM1 mutation with good sensitivity and repeatability, which can be used for screening NPM1 mutation in newly diagnosed AML patients and for minimal residual disease monitoring after remission in positive AML patients to guide treatment.

Research Advance of Gene Mutation and Targeted Drug Therapy in Childhood Acute Myeloid Leukemia --Review / 中国实验血液学杂志

The clinical therapeutic regimen for acute myeloid leukemia (AML) is not significantly different between adults and children, which is mostly based on IA (idarubicin and cytosine arabinoside) induction chemotherapy. With the rapid development of sequencing technique, people's understandings towards the molecular and biological abnormalities of AML are increasing, diverse AML gene mutation-based targeted drugs have been rapidly developed and applied. In this review, several commonly gene mutations in AML (such as FLT3, NPM1 and C/EBPA) was described, and the therapeutic effects and differences of targeted drugs that used in clinical treatment or had been reported (like tyrosine kinase inhibitor, IDH1 mutation inhibitor and epigenetic modification inhibitor) in child and adult AML patients were summrized.

Analysis of Coexisting Gene with NRAS in Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To investigate the coexisting mutations and clinical significance of Homo sapiens neuroblastoma RAS viral oncogene homolog (NRAS) gene in acute myeloid leukemia (AML) patients.@*METHODS@#High-throughput DNA sequencing and Sanger sequencing were used to detect 51 gene mutations. The occurrence, clinical characteristics and treatment efficacy of coexisting genes with NRAS were investigated.@*RESULTS@#A total of 57 NRAS mutations (17.5%) were detected in 326 patients with AML. Compared with the patients in NRAS non-mutation group, patients in the mutant group were younger (P=0.018) and showed lower platelet count (P=0.033), but there was no significant difference in peripheral leukocyte count, hemoglobin, and sex. For FAB classification, NRAS mutation and M2 subtype showed mutually exclusive (P=0.038). Among 57 patients carried with NRAS mutation, 51 (89.5%) patients carried with other gene mutations, 25 (43.9%) carried with double gene mutations, 10 (17.5%) carried with 3 gene mutations, and 16 (28.1%) corried with ≥ 4 gene mutations. The most common coexisting gene mutation was KRAS (24.6%, 14/57), followed by FLT3-ITD (14.0%, 8/57), RUNX1 (12.3%, 7/57), NPM1 (10.5%, 6/57), PTPN11 (10.5%, 6/57), DNMT3A (10.5%, 6/57) and so on. The age (P=0.013, P=0.005) and peripheral platelet count (P=0.007, P=0.021) of patients with NPM1 or DNMT3A mutations were higher than those of the patients with wild type, but there was no significant difference in peripheral leukocyte count and hemoglobin. Also, there was no significant difference in age, peripheral leukocyte count, hemoglobin, and peripheral platelet count between the patients in KRAS, FLT3-ITD, RUNX1 or PTPN11 mutant group and the wild group. Patients with FLT3-ITD mutations showed a lower complete remission (CR) rate (P=0.044). However, there was no significant difference in CR rate between the patients with KRAS, NPM1, RUNX1, PTPN11 or DNMT3A mutations and the wild group. The CR rate of the patents with single gene mutation, double gene mutations, 3 gene mutations, and≥ 4 gene mutations were decreased gradually, and there was no significant difference in CR rate between pairwise comparisons.@*CONCLUSION@#The mutation rate of NRAS mutation is 17.5%, 89.5% of AML patients with NRAS mutation coexist with additional gene mutations. The type of coexisting mutations has a certain impact on clinical characteristics and CR rate of patients with AML.

Association of Next Generation Sequencing Based Genotypic Profiling with MICM Characteristics in NPM1 Mutated Acute Myeloid Leukemia / 中国实验血液学杂志

OBJECTIVE@#To explain the clinicobiological heterogeneity of NPM1 mutated (NPM1mut) acute myeloid leukemia (AML) by analyzing the association between next-generation sequencing (NGS) profiles and MICM characteristics in patients with this AML subtype.@*METHODS@#Data of 238 NPM1mut patients with available NGS information on 112 genes related to blood disease was collected, and χ2 test and nonparametric test were used to analyze the distribution association between NGS-detecting mutations and conventional MICM parameters.@*RESULTS@#In entire NPM1mut cohort, totaling 240 NPM1 mutation events were identified, of whom 10 (10/240, 4.2%) were missense mutations, which did not involve any W288 or W290 locus and were found exclusively in NPM1mut/FLT3-ITD- group. All but one of these missense mutations (9/10, 90%) were accompanied by AML subtype-defining recurrent cytogenetic or molecular abnormalities, of which 7 cases were in the low risk and 2 in the high risk. NPM1mut occurred solely as an insertion/deletion (indel) type in the NPM1mut/FLT3-ITD+ group. The incidence of favorable plus unfavorable karyotypes in NPM1mut/FLT3-ITD- group was higher than in NPM1mut/FLT3-ITD+ group (6.4% vs. 0, P=0.031). The positive rates of CD34 and CD7 in NPM1mut/FLT3-ITD+ group were significantly higher than in NPM1mut/FLT3-ITD- group (CD34: 47.9% vs. 20.6%, P<0.001; CD7: 61.5% vs. 29.9%, P<0.001). Logistic analysis showed that FLT3-ITD independently predicted for CD34+ and CD7+ [odds ratio (OR)=5.29, 95%CI: 2.64-10.60, P<0.001; OR=3.47, 95%CI: 1.79-6.73, P<0.001; respectively]. Ras-pathway mutations independently predicted for HLA-DR+ (OR=4.05, 95%CI: 1.70-9.63, P=0.002), and KRAS mutation for MPO- (OR=0.18, 95%CI: 0.05-0.62, P=0.007). TET2/IDH1 mutations independently predicted for CD34- and CD7- (OR=0.26, 95%CI: 0.11-0.62, P=0.002; OR=0.30, 95%CI: 0.14-0.62, P=0.001; respectively), and MPO+ (OR=3.52, 95%CI: 1.48-8.38, P=0.004). DNMT3A-R882 independently predicted for CD7+ and HLA-DR+ (OR=3.59, 95%CI: 1.80-7.16, P<0.001; OR=13.41, 95%CI: 4.56-39.45, P<0.001; respectively), and DNMT3A mutation for MPO-(OR=0.35, 95%CI: 1.48-8.38, P=0.004).@*CONCLUSION@#Co-existing FLT3-ITD in NPM1mut AML independently predicts for CD34+ and CD7+, co-existing Ras-pathway mutation for HLA-DR+ and MPO-, co-existing TET2/IDH1 mutation for CD34-, CD7-, and MPO+, and co-existing DNMT3A mutation for HLA-DR+, CD7+, and MPO-, thereby providing a new mechanism explanation for the immunophenotypic heterogeneity of these AML patients.

Clinical Characteristics of Acute Myeloid Leukemia Patients with RUNX1 Gene Mutation / 中国实验血液学杂志

OBJECTIVE@#To investigate the incidence of Runt-related transcription factor 1 (RUNX1) gene and its associated gene mutations in patients with acute myeloid leukemia (AML), and analyze its clinical characteristics and prognosis.@*METHODS@#The genomic DNA-PCR method was used to detect the exon of RUNX1 gene, and the gene mutations were analyzed by genetic sequencing. NPM1, DNMT3A, FLT3-ITD, IDH1/2, K/N-RAS, CEPBA, TET2, and WT1 co-mutations were also detected. Patients were followed up to determine efficacy and prognosis.@*RESULTS@#Among 171 patients, the RUNX1 gene mutation was detected in 17 cases, and the mutation rate was 9.9%. The type of RUNX1 gene mutation was 9 missense mutations, 4 frameshift mutations, and 4 nonsense mutations. The peripheral blood leukocyte count of the patients in mutation group was 3 (1-101) ×10@*CONCLUSION@#AML patients with RUNX1 gene mutation shows unique clinical and biological characteristics, RUNX1 mutation can be regarded as a molecular marker of poor prognosis in AML patients.

Analysis of induction efficacy and prognostic factors in FLT3-ITD positive acute myeloid leukemia in the real world / 中华血液学杂志

Objective: To investigate the efficacy and prognostic factors of induction therapy in FLT3-ITD(+) acute myeloid leukemia (AML) in the real world data. Methods: From January 2013 to December 2016, 114 de novo patients with FLT3-ITD(+)AML were enrolled in this study. Out of 114 cases, 75 were male, and 39 were female. The median age was 42 years old (ranged from 14 to 72 years old) . The chemotherapy regimens were used for induction therapy and all cases were followed up. The treatment response was evaluated by MICM and the comparison of the ratio were analyzed by chi-square test and the survival was estimated by Kaplan-Meier analysis and Cox proportional hazards model was used to identify independent prognostic factors. Results: There were 52 FLT3-ITD(+)AML patients with favorable prognosis genes (46 cases with NPM1, 5 cases with RUNX1-RUNX1T1, 1 case with CEBPA double mutation) and 62 patients with other types of FLT3-ITD(+)AML at diagnosis. All patients completed at least one cycle of induction therapy and the clinical curative effect was evaluated, complete remission (CR) rate was 50.0% (57/114) in one cycle and total CR rate was 72.5% (74/104) in two cycles. The CR rate of the FLT3-ITD(+) AML patients with favorable prognosis genes was 67.3% (35/52) in one cycle and 83.3% (40/48) in two cycles; for the other types FLT3-ITD(+)AML patients, the CR rate was 35.5% (22/62) in one cycle and 64.8% (35/54) in two cycles. There was a significant difference in CR rate between the FLT3-ITD(+)AML patients with and without favorable prognosis genes (P<0.05) . This indicates that the FLT3-ITD(+)AML patients with favorable prognosis gene had relatively good therapeutic effect. Among other types of FLT3-ITD(+)AML patients who did not achieve remission from one cycle of chemotherapy, 9 patients were given sorafenib plus chemotherapy and 6 cases (66.7%) achieved CR; 23 patients were given conventional chemotherapy and 7 cases (30.4%) achieved CR. There was a significant difference between sorafenib plus chemotherapy and conventional chemotherapy groups (χ(2)=4.47, P<0.05) and this indicates that sorafenib plus chemotherapy can significantly improve the CR rate of FLT3-ITD(+)AML patients. Comparing overall survival (OS) and disease free survival (DFS) , there was no significant difference between sorafenib plus chemotherapy and conventional chemotherapy groups (P values were 0.641 and 0.517, respectively) . Conclusion: The overall prognosis of FLT3-ITD(+)AML patients is poor, and the stratification therapeutic efficacy of FLT3-ITD(+)AML without favorable prognosis gene can be improved by sorafenib combined with chemotherapy.

Age-related clinical characteristics and prognosis in non-senile adults with acute myeloid leukemia / 中华血液学杂志

Objective: To explore age-related clinical characteristics, early responses and outcomes in non-senile adults with de novo acute myeloid leukemia (AML). Methods: Data of consecutive cases of 18-65 years adults with de novo AML (non-acute promyelocytic leukemia) were reviewed retrospectively. Clinical characteristics at diagnosis, early responses and outcomes across different age groups of patients were analyzed. Results: 1 097 patients were enrolled. 591 (53.9%) were male. Median age was 42 years. Increasing age was significantly associated with decreasing WBC count (P=0.003), increasing PLT count (P=0.034), lower blast proportions in bone marrow (P=0.021). The incidence of NPM1(+)/FLT3-ITD(-) increased with age (P<0.001). Multivariate analyses showed that increasing age was associated with low probabilities of achieving morphologic leukemia free state (MLFS) (P=0.053) and complete remission (CR) (P=0.004) and poor overall survival (OS) (P=0.070) in the whole patients population. However, increasing age was not associated with low MLFS rate and poor OS, except low CR rate (P=0.075) in those receiving standard induction regimen instead of low-intensity regimen. Conclusions: There were significant differences on clinical characteristics, cytogenetics and molecular genetics across different age groups in non-senile adults with de novo AML. In the patients receiving standard induction regimen, age was not associated with MLFS rate and OS.

Effect of FLT3-ITD with DNMT3A R882 double-mutation on the prognosis of acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation / 中华血液学杂志

Objective: To investigate the impact of FLT3-ITD and DNMT3A R882 double mutations to the prognosis of acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: FLT3-ITD, DNMT3A, C-kit, CEBPA, FLT3-TKD and NPM1 mutations were detected in 206 newly diagnosed AML patients by Sanger sequencing (M(3) and those received FLT3 inhibitor were excluded). Clinical data of AML patients were retrospectively analyzed to compare the prognosis of each gene mutation group. Results: ①Of 206 patients, 104 were male and 102 female with a median age of 38 (3-63) years, including 6 cases of M(0), 24 cases of M(1), 56 cases of M(2), 39 cases of M(4), 63 cases of M(5), 6 cases of M(6) and 12 unclassified cases. ②All 206 patients were divided into four groups according to the mutation gene at the time of diagnosis: FLT3-ITD(+) DNMT3A R882(+) group (group A), FLT3-ITD(+) DNMT3A R882(-) group (group B), FLT3-ITD(-) DNMT3A R882(+) group (group C) and FLT3-ITD(-) DNMT3A R882(-) groups (group D). Gender, leukocyte count at diagnosis, chromosome karyotype, the median age, FAB classification, disease status prior to transplantation, type of donor, conditioning regimen and GVHD were not significantly different between four groups (P>0.05). ③The 2-year cumulative recurrence rate (CIR) of group A was significantly higher than that of other groups [group A (72.2±2.6)%, group B (38.6±0.6)%, group C (36.8±1.6)%, group D (27.8±0.1)%, respectively, P<0.05], while the 2-year overall survival (OS) rate and 2-year leukocyte-free survival (LFS) rate were lower than those of other groups [group A (30.9±13.3)%, (11.3±10.2)%; group B (67.5±7.8)%, (47.9±8.4)%; group C (61.4±12.4)%, (56.8±12.5)%; group D (80.1±3.7)%, (79.7±3.6)%, respectively, P<0.05]. Conclusion: AML patients with FLT3-ITD and DNMT3A R882 double mutations had a very high CIR and low OS, LFS after transplantation.