Clinical Application Analysis Of NGS Detection In 127 Cases Of Non-small Cell Lung Cancer

Based on the demand of molecular typing precision therapy,next generation sequencing（NGS）,as a new detection method,points out the direction for the accurate selection of targeted therapy for lung cancer.In this study,NGS was used to analyzed the landscape of gene mutation in patients with non-small cell lung cancer（NSCLC）.To explore the effects of EGFR single gene mutation with multi-gene co-mutation and TP53 mutation on the prognosis of NSCLC patients,and to provide a theoretical basis for predicting the efficacy and drug resistance mechanism of targeted therapy in advanced NSCLC patients,so as to comprehensively evaluate the guiding role of NGS technology in NSCLC therapy.This study collected 127 patients with NSCLC in Air Force characteristic Medical Center from January 2016 to March 2020.The samples of tumor tissue and blood were collected before treatment and progressive disease（PD）,and the gene sequencing of the results were carried out by the NGS of 1021 gene Panel.Those results combined with clinical data were analyzed by IBM SPSS 25.0 Statistics software.On the basis of the NGS results of 127 NSCLC patients,123（96.85%）of them detected gene mutation,4 patients（3.15%）were negative。The mutation frequency of EGFR and TP53 were the higher in 78 cases（61%）and 72 cases（57%）.EGFR and TP53 gene as a keynote to analysised in this paper.To analyze the relationship between EGFR、TP53 gene and the characteristics of different cases in 127 patients with NSCLC in stage IIIB、IIIC and IV,Female（χ²=16.994,P=0.000）,old age（χ²=4.237,P=0.040）,non-smoking（χ²=12.801,P=0.002）,advanced（χ²=8.271,P=0.004）,lung adenocarcinoma（χ²=8.984,P=0.003）patients had more EGFR mutation.However,sex（χ²=2.854,P=0.091）,age（χ²=0.660, P=0.417）,smoking history（χ²=3.231,P=0.199）,pathological type （χ²=0.138,P=0.710）,TNM stage（χ²=0.055,P=0.814）,above all of those characteristics were no significant with TP53 mutation.Somatic mutations differ in adenocarcinoma and squamous carcinoma with different states of EGFR mutations（χ²=21.921,P=0.000）.In 75 of 127 patients with NSCLC,they were positive for EGFR mutation;8 patients with EGFR-TKIs combined chemotherapy or vascular targeting currently maintain partial remission（PR）.67 patients advanced NSCLC with EGFR mutation were PD after treatmented with Gefitinib or Ictiniband,and underwent NGS detection again.The detection of 1021 gene Panel NGS at baseline found 108 genes accompanied by EGFR mutation.At baseline,the range of somatic mutation was 1～24,and the median number of somatic mutation was 4;Only the EGFR mutation group was a single mutation group,EGFR at least one with other gene mutation group was a co-mutation group,in the high co-mutation group that the number of somatic mutation was higher than the median somatic mutation,and the low mutation group was between them.EGFR single mutation group were 16 cases（23.88%）,low mutation group were 14 cases（20.90%）,high mutation group were 37 cases（55.22%）.1021 gene Panel NGS test at PD,A total of 120 mutations were detected,Among of them,15 patients （22.28%）found EGFR the mutation disappeared,T790M mutation occurred in 22 cases（32.83%）.At the time of progression,there were 0～28somatic mutation,The median number of somatic mutation was 3.To explore the changes of genes in 67 NSCLC patients before and after targeted therapy,we compared the baseline and all the mutated genes at the time of progression.We found that there were 50 genes（29.4%）were disappeared by first-line targeted therapy,62 new genes（36.5%）were emerged when PD and 58 genes mutation（34.1%）unchanged.Compared with the baseline,the number of somatic mutation was decreased,but the difference between the two groups was not statistically significant （P=0.338）.By March 2020,67 NSCLC patients with advanced EGFR mutation after first-line targeted therapy,All progressed（100%）,34 cases were death（50.75%）,m PFS was 11.60 months,m OS was 37.10 months.1.age effects on patient PFS、OS:m PFS and m OS of patients with≧60 years old was shorter than that of<60 years old,m PFS were（9.5±1.2）months vs.（12.6±1.1）months,m OS were（12.0±0.1）months vs.（18.0±1.4）months,we found a significant difference in PFS and OS(P_PFS=0.006;P_OS=0.041).2.EGFR co-mutation effects on patient ORR:ORR in EGFR single mutation vs.low co-mutation vs.high co-mutation was 68.75%vs.57.14%vs.32.43%,respectively（P<0.05）.3.EGFR co-mutation effects on patient PFS、OS:m PFS in EGFR single mutantion vs.low co-mutation vs.high co-mutation was（17.2±1.30）vs.（12.1±1.0）vs.（8.9±0.6）months, respectively（p=0.000）.Patients with EGFR single mutantion group （27.5±5.1）months showed significantly longer OS than those with low co-mutation group（21.5±2.3）months or high co-mutation group（12.3±1.2months）（P=0.003）.Of 67 advanced EGFR positive NSCLC patients,TP53 mutation was found to be the highest rate associated EGFR mutation at baseline.TP53mutation with patient outcomes was analysised,m PFS of patients with TP53 wild type was（14.8±1.0）months compared to（9.3±0.6）months in patients with TP53 mutantation（P=0.000）;m OS in patients with TP53 wild type was（23.8±2.8）months vs.（13.5±1.3）months in patients with TP53mutantion（P=0.001）.EGFR positive lung adenocarcinoma patients with TP53 mutantion who outcome was shorter than that patients with TP53wild type.Cox multivariate regression analysis showed that old age,EGFR co-mutation and TP53 mutation were independent risk factors for PFS （P=0.010,P=0.001,P=0.003）.old age,EGFR co-mutation,and TP53 gene mutation are also risk factors for OS（P=0.014,P=0.001,P=0.000）.elderly,EGFR co-mutation,TP53 mutation are the factors that affect the poor prognosis of patients.To sum up,1.Co-mutation is closely related to the efficacy of EGFR-TKIs in advanced NSCLC patients with EGFR mutation.The fewer co-mutantion genes and lower clone heterogeneity,the more obvious benefits from EGFR-TKIs.Treated by EGFR-TKIs,patients with poor efficacy who are often accompanied by more co-mutantion and a high degree of clonal heterogeneity.2.Accompanied by TP53 mutation suggest poor prognosis for NSCLC patients with EGFR positive mutation.3.large Panel gene NGS technique be used for tissue and liquid biopsy can detect a variety of common,rare and multi-gene mutation types for lung cancer, which provides reliable support for precision therapy and individualized therapy.4.NGS technology is helpful to discover the drug resistance mechanism of targeted therapy and is a major advantage in guiding the follow-up accurate treatment of advanced NSCLC.