| BackgroundAcute Myeloma Leukemia(AML)and Myelodysplastic Syndrome(MDS)are a group of heterogeneous diseases with characterized clinical and biological features.About 30%-40%of patients with MDS will eventually transformed into AML.The theory of clonal evolution is one of the more concerned mechanisms at present.The clinical application of the next-generation sequencing(NGS)technology enable us to understand that gene mutations play an important role in the pathogenesis of MDS and AML.Comparing the changes in the mutation profiles of AML and MDS is helpful to understand the pathogenesis of AML and MDS,and to identify a progenitor gene signature subtype associated with a high risk of AML transformation.However,there is still a large prognostic heterogeneity among AML with the same gene mutation.The impact of the Variant Allele Frequency on the prognosis of patients with AML has attracted more and more attention.Currently,the allelic burden of ASXL1 mutation at the time of diagnosis of AML has not been well evaluated for its prognostic impact on survival.Further characterization of the variant allele frequency(VAF)of ASXL1 mutation by next-generation sequencing and its impact on patient outcomes might lead to better risk stratification of patients with newly diagnosed AML.ObjectiveThis study analyzed the differences in gene mutation profiles of AML and MDS and the effect of age on the gene mutation profiles of AML and MDS.We also evaluated the prognostic impact of the VAF of ASXL1 mutation in patients with newly diagnosed AML.Trying to elaborate the possible mechanism of AML and MDS development and the role of ASXL1 gene in the development of AML.Material and methodsA total of 670 newly diagnosed AML(non-M3)patients and 218 MDS patients admitted to the First Affiliated Hospital of Zhengzhou University from June 2016 to January 2019 were collected,and all patients were applied with AML/MDS-NGS gene chip after written consent.Bone marrow fluid was tested for 22 common AML mutant genes.All patients were diagnosed and typed according to the WHO(2016)standard,and the risk stratification was performed using the 2017 Chinese version of adult acute myeloid leukemia diagnosis and treatment guidelines.This study was approved by the Ethics Committee of Zhengzhou University(ethical batch number:2019-KY-194).Analyze the differences in age,gender,number of gene mutations,and positive rates of gene mutations in patients with AML and MDS;screen out 35 patients with ASXL1 gene-positive AML(ASXL1+ AML,non-M3)and analyze their general clinical characteristics Blood routine,age,gender),concomitant gene mutations,and the effect of VAF on prognosis.The data were analyzed using SPSS 2 5.0.The figures were drawn using GraphPad Prism 8.0.ResultsPart1.Analysis of gene mutation profiles in patients with AML and MDS.1.1 Comparison of general clinical characteristics and positive rates of 22 gene mutations in patients with AML and MDS.670 newly diagnosed patients with AML,with a median age of 48.5 years(14-86 years),357 male vs 313 female;the median age of 218 patients with MDS was 54 years(17-86 years),and 122 male vs 96 female.At least one gene mutation was detected in 65.1%of MDS patients and 81.3%of AML patients,respectively.The positive rate of gene mutation in AML patients was significantly higher than that in MDS(?2=24.668,p<0.05);The incidence of NPM1?CEBPA?NRAS?FLT3?DNMT3A?KIT?IDH2 and IDH1genes in AML was higher than that of MDS(p<0.05);the incidence of ASXL1?U2AF1?CBL?EZH2?SETBP1?SF3B1 and SRSF2 genes was higher in MDS than that in AML(p<0.05).The positive rates of TET2?RUNX1?TP53?PHF6?JA K2?ZRSR2?ETV6 genes were not different between AML and MDS.1.2 The impact of age on gene mutations in patients with AML and MDS.The genetic mutation profiles of patients with AML and MDS are different in different age groups.The positive rates of NPM1?CEBPA?NRAS?FLT3?DNMT3A?IDH2?IDH1?TET2 and KIT mutations in the young AML patients were significantly higher than MDS,and the incidence of ASXL1?U2AF1?TP53?CEL and SETBP1 was significantly lower than in MDS.In the elderly AML patients,the positive rate of NPM1,FLT3,DNMT3A,CEBPA and IDH2 gene mutations was significantly higher than that of MDS,and only the positive rate of U2AF1,SF3B1 gene mutations was significantly lower than MDS.Part2.Clinical characteristics and prognosis of patients with ASXL1+AML2.1 Analysis of clinical characteristics of patients with ASXL1+AMLOf the 27 ASXL1+AML patients,17 were male(62.96%)and 10 were female(37.04%).The median age was 44(20-73)years old.The median white blood cell count was 5.7(0.66-307)× 109/L,median hemoglobin count 77.7(42-135)g/L,median platelet count 43(5-423)× 109/L;M2 was the most common(n=19,70.4%),followed by M5(14.8%),M0(7.4%),M4(3.7%)and AML are not classified(3.7%),21 cases in high-risk group(77,78%),3 cases in intermediate-risk group(11.11%),3 cases in low-risk group(11.11%)The median follow-up time was 294.5(11-800)days.Of the 24 patients with complete data for efficacy analysis,19 patients(79.2%)achieved complete remission after 1 or 2 courses,and 2 patients relapsed(8.3%).2.2 Analysis of gene mutations and concomitant gene mutations in patients with ASXL1+AMLA total of 20 mutation sites were detected in 27 ASXL1+AML patients,all of which were located on exon 12.The incidence rates were 22.22%for H630fs,11.11%for G642fs,and 7.4%for G643fs,G652S?N986S and the other 15 mutation sites occurred at 3.70%.The H630fs mutation had no effect on the 1-year survival rate of ASXL1+AML patients compared with other mutations(83.3%,95%CI0.127-1.000 vs 35.9%,95%CI0.835-1.000,?2=0.194,p=1.690).24 patients were accompanied by other gene mutations(88.9%).The most common gene was U2AF1(33.3%),followed by RUNX1(21.7%),FLT3(16.7%)and IDH2(16.7%)genes.NPM1 and IDH1 mutations were not detected.23 out of 27 ASXL1+AML patients were screened for fusion genes with a result of AML1-ETO in 6 cases(26.1%),CBF?-MYH11 in 2 cases(8.7%)and BCR-ABL in 1 case(4.3%).AML1-ETO had no effect on the prognosis of AML patients with ASXL1(8.3%,95%CI 0.535-1.000 vs 31.7%,95%CI 0.096-0.538,x2=3.414,p=0.065).2.3 Analysis of VAF value in ASXL1+AML patients and its impact on prognosis.The median VAF of the ASXL1 gene was 37.92%(1.28%-65.83%).The ASXL1+AML patients were divided into ASXL1 high mutation burden group(ASXL1highAML,ASXL1 VAF>37.92%,n=13)and ASXL1 low mutation burden group(ASXL1lowAML,ASXL1 VAF?37.92%,n=14).The 1-year survival rate(15.4%,95%CI0.000-0.350 vs 77.1%,95%CI 0.542-1.000,x2=9.775,p=0.002)and the event free survival rate(15.4%,95%CI0.000-0.350 vs 62.9%,95%CI0.368-0.889,?2=7.651,p=0.006)in the ASXL1highAML group was significantly lower than that in the ASXL1lowAML group.The multivariate analysis found that ASXL1 high VAF>37.92%was an independent risk factor for the prognosis of the ASXL1+AML patients.Conclusion1.Compared with MDS,Patients with AML is more likely to incorporate gene mutations.2.There are differences in the mutation profiles of AML and MDS.NPM1,CEBPA,NRAS,FLT3,DNMT3A,IDH2 genes have a higher incidence in AML(mutation frequency>10%),while ASXL1,U2AF1 genes are more common in MDS(mutation frequency>10%)3.Age is a influencing factor of gene mutation spectrum in patients with AML and MDS.The difference in gene mutation spectrum between elderly patients with AML and MDS is relatively small.In the young patients,the positive rates of NPM1,CEBPA,NRAS,FLT3,DNMT3A,IDH2,IDH1,TET2 and KIT gene mutations in patients with AML were significantly higher than that in MDS,The incidence of ASXL1,U2AFl,TP53,CBL and SETBP1 mutations in AML were significantly lower than that in MDS;while in elderly AML patients,the positive rates of NPM1,FLT3,DNMT3A,CEBPA and IDH2 gene mutations were higher than that in MDS,while the positive rates of U2AF1 and SF3B1 gene mutations were lower than that in MDS4.The mutation rate of ASXL1 gene mutation in AML is low(5.2%).ASXL1 gene mutation often combined with other gene mutations.U2AF1 mutations have the highest incidence,followed by R UNX1 and FLT3 mutations5.High ASXL1 mutant allele burden is a poor prognostic factor for ASXL1+AML. |
PDF Full Text Request