Mutational Spectrum And Prognosis Analysis Of AML Patients Based On High-throughput Sequencing

Objective:The purpose of this study was to describe the mutational spectrum in 34genes associated with blood tumors based on High-throughput sequencing in patients with acute myeloid leukemia(AML),and to observe the co-occurrence and mutual exclusion of mutations.Analysis of the correlation between mutation and clinical features.The relationship between gene mutation and prognosis of intermediate-risk AML(IR-AML)patients and the influencing factors of prognosis in this kind of patients were analyzed emphatically.Methods:93 newly diagnosed AML patients were collected at our Hospital between March 2014 and April 2018.We applied the High-throughput sequencing(HTS)techni-que to screen the mutations of 34 genes associated with blood tumors.Described the mutational spectrum,analysis the co-occurrence and mutual exclusion between the mutant genes.We used statistical methods to analyze the correlation between mutant genes and clinical features,including age,sex,white blood cell count,platelet count,hemoglobin content,lactate dehydrogenase,proportion of bone marrow primordial cells,extramedullary infiltration,Immunophenotyping,CR rate after twice induction chemotherapy,etc.To analyze the correlation between mutant gene and prognosis of IR-AML patients and the influencing factors of prognosis in this kind of patients.Results:(1)82 of 93 AML patients(88.17%)had at least one gene mutation,and the mutation pattern of polygene mutation(≥2)was common,[53.76%(50/93)].Also in IR-AML[50.72%(35/69)].The mutation frequency of the following 8 genes was more than 10%(CEBPA,ASXL1,TET2,NRAS,FLT3-ITD,NPM1,IDH2,DNMT3A)in 93AML patients,and the mutation frequency of CEBPA was the highest(20.4%).(2)Several overlapping mutation patterns of co-occurrence and possible mutual exclusion were identified by genetic interaction analysis.It was found that the mutated genes IDH1/2 and NPM1,ASXL1 and U2AF1,FLT3 and NPM1 often co-occurrence(p<0.05).On the contrary,K/NRAS mutation may be mutually exclusive with TET2,NPM1,IDH1/2,RUNX1,KIT mutations,NPM1 mutation may be mutually exclusive with K/NRAS,RUNX1,GATA2,U2AF1 mutations,DMNT3A mutation may be mutually exclusive with CEBPA mutation.KIT gene mutation may be mutually exclusive with FLT3 and K/NRAS gene mutations.(3)There is a certain correlation between the mutant gene and clinical features.ASXL1 gene mutations were more common in patients over 50 years of age,and NPM1gene mutations were more common in patients over 35 years of age.FLT3-ITD gene mutation was associated with high WBC and LDH.KIT gene mutation was associated with high LDH.CEBPA double mutation was associated with high WBC.U2AF1 gene mutation was associated with lower WBC,Hb and LDH.CEBPA mutation was associated with a higher positive rate of CD7.DNMT3A mutation was associated with a lower positive rate of CD33.IDH2 mutation was associated with lower positive rates of CD13 and MPO.FLT3-ITD mutation is associated with lower MPO positive rate.(4)In the analysis of CR rate after two courses of chemotherapy and mutant gene in 57 IR-AML patients,it was found that the CR rate of TET2,GATA2,CSF3R mutation group was significantly higher than that of wild type group,but the difference was not statistically significant.The CR rate of SF3B1(p=0.041),DNMT3A,IDH2 mutation group was significantly lower than that in wild type group,but there was no statistically significant in DNMT3A,IDH2 mutation group.Stepwise selection logistic regression analysis showed that only DNMT3A mutation was identified as a disadvantage for the realization of CR.(5)In the analysis of mutation gene and prognosis of 57 IR-AML patients,it was found that IDH2 mutation was associated with poor OS and PFS(p<0.05).The OS and PFS of TET2 mutation were worse than those of wild type,but the difference was not statistically significant.The OS of ASXL1 mutation was worse than that of wild type,and the PFS of DNMT3A mutation was worse than that of wild type,but there was no significant difference between them.(6)COX multivariate analysis of 57 IR-AML patients confirmed that the Age≥50years(HR:3.593,95%CI:1.372-9.408,p=0.009),WBC>100×10~9/L(HR:6.381,95%CI:1.362-29.902,p=0.019),Anemia at the time of first diagnosis(HR:10.721,95%CI:1.294-88.820,p=0.028),CD22(+)(HR:11.281,95%CI:1.582-80.427,p=0.016)were the independent factors of poor OS.Age≥50years(HR:6.072,95%CI:1.757-20.981,p=0.004),WBC>100×10~9/L(HR:5.606,95%CI:1.287-24.410,p=0.022),anemia at the time of first diagnosis(HR:4.335,95%CI:1.026-18.322,p=0.046),CD34(+)(HR:6.472,95%CI:1.537-27.247,p=0.011),IDH2 mutation(HR:6.111,95%CI:1.444-25.868,p=0.014)was an independent factor for poor PFS.CR after induction(HR:0.231,95%CI:0.075-0.709,p=0.010)is an independent factor for better PFS.Conclusion:In the comprehensive genome analysis based on High-throughput sequencing technology,the gene mutation spectrum of AML patients was described,and several co-occurrence and possible exclusive mutation patterns were found.The potentially important relationship between mutated genes provide a theoretical basis for a comprehensive understanding of pathogenesis of AML.By exploring the relationship between mutations and clinical features,it is shown that there is a specific correlation between gene mutations and clinical features,but in turn it is very difficult to infer the clinical characteristics of patients from specific gene mutations.Further research is needed to explore the relationship between different combinations of gene mutations and clinical features.Most importantly,by analyzing prognostic factors from multiple angles in IR-AML patients,it was found that the Age≥50 years,WBC>100×10~9/L,Anemia at first diagnosis,CD22(+),CD34(+),failure to reach CR after two courses of induction chemotherapy,and the presence of IDH2 gene mutation were associated with poor prognosis.What needs to be mentioned in particular is the IDH2 gene mutation,it may be a factor that can be used to establish a new and more effective risk stratification model of IR-AML,and provide a certain theoretical basis for improving the prognosis evaluation system of this kind of patients and the next step of individualized treatment.