Detection Of Multi-driver Gene And TP53 Gene In Peripheral Blood Of Patients With Advanced Non-small Cell Lung Cancer And Prognostic Effects Of Gene Co-mutation

Background and purposeNon-small-cell lung cancer(NSCLC)with many histological subtypes,is one of the tumors with the most genetic and biological diversity,and its prevention and treatment face great challenges.With the development of molecular biology,significant progress has been made in the study of the key molecular and cellular mechanisms driving tumor development in NSCLC.In the past decade,a variety of new targeted drugs have been developed,resulting in new therapeutic strategies.The treatment strategy for advanced NSCLC patients has shifted from empirical selection based on clinicopathological features to biomarkers based on tumor-driven molecular structural changes in patients.For example,when the common driver gene in NSCLC patients is the epidermal growth factor receptor(EGFR)gene or the anaplastic lymphoma kinase(ALK)gene is mutated,the NCCN guidelines recommend that tyrosine kinase inhibitors(TKI)be preferred for first-line treatment.EGFR mutation status is an important predictor of the efficacy of EGFR tyrosine kinase inhibitors(EGFR-TKI)in NSCLC treatment.Genotype-based targeted therapy is the first step to realize individualized precision therapy for NSCLC.Cyclic single molecule amplified resequencing(cSMART)has been used for the first time in noninvasive prenatal testing(NIPT)to detect circulating fetal allele mutations in maternal plasma.Preamplify a single allele molecule using a unique bar code.cSMART counts only once,eliminates the potential PCR size bias,and more accurately quantifies the percentage of mutant alleles in the plasma sample.This next-generation sequencing technology enables rapid and comprehensive sequencing of the genomes of individual tumor patients from the plasma of small tumor patients.This technological advance is conducive to the classification of NSCLC patients at the molecular subgroup level,thus increasing methods for clinical evaluation of the efficacy of molecular targeted therapy and the discovery of new drug targets.At present,there is no uniform standard on how to select,interpret and apply the results of gene and genome analysis.There are few reports on the application of genotyping and genomic detection in NSCLC treatment decision making.In this study,the variation of multiple driver genes and tumor suppressor gene TP53 in peripheral blood of patients with advanced NSCLC was analyzed to explore their roles and clinical significance in targeted therapy of advanced lung cancer.The effects of co-mutations of EGFR/TP53 and EGFR/PIK-3CA genes on the efficacy of EGFR-TKIS in patients with advanced NSCLC were also investigated.Meterials and MethodsUsing cSMART technology detecting common drive gene in 96 NSCLC patients peripheral blood[epidermal growth factor receptor(EGFR),phosphatidyl inositol kinase-3 catalytic subunit of alpha(PIK3CA),rat sarcoma viral on cogene homologous body B1(BRAF),anaplastic lymphoma kinase(ALK),rat sarcoma virus oncogenes(KRAS),human epidermal growth factor receptor 2(HER2),interstitial epithelial conversion factor(MET),gene transduction rearrangement(RET),Sarcoma carcinogenic factor-receptor tyrosine kinase(ROS1)]and tumor suppressor gene p53 protein(TP53)mutations situation,analysis the genetic relationship with NSCLC patients with clinical pathological index,analysis of EGFR mutation rate of the highest ctDNA with NSCLC patients with clinical pathological indicators and analyzes the relationship between EGFR/TP53,EGFR/PIK3CA gene co-mutation and clinical characteristics of relationship,and survival analysis,using multiariable Cox regression model analysis of EGFR/TP53 relationship between co-mutation of EGFR/PIK3CA gene and the efficacy and prognosis of EGFR-TKIs.Results1.96 patients with advanced NSCLC had mutation detection rates of EGFR,TP53,KRAS,PIK3CA and MET genes of 44.80%,14.60%,10.40%,9.38%and 4.17%,respectively,mutation detection rates of ALK and HER2 genes of 2.10%,and positive fusion detection rates of ALK and ROS1 respectively.The detection rate of adenocarcinoma/adenocarcinoma with neuroendocrine carcinoma hotspot genes was higher than that observed in squamous cell carcinoma patients.There was no significant correlation between EGFR,TP53,KRAS,PIK3CA gene mutation and clinicopathology.2.Among the EGFR positive patients,44.2%(19/43)had a single mutation of EGFR,20.9%(9/43)had double or triple mutations,and 34.9%(15/43)had mutations in other drug-resistant genes of TP53,KRAS and PIK3CA.The concentration of EGFR ctDNA in the age group≤60 years was higher than that of>age group(P<0.05).3.In the 43 patients with positive mutation of EGFR gene,30 were single mutation of EGFR gene,7 were EGFR/TP53 gene co-mutation,and 6 were EGFR/PIK3CA gene co-mutation.The progression-free survival time(PFS)of first-line patients of NSCLC with EGFR-TKIs treated with the singal mutation of EGFR was longer than that of patients of NSCLC with EGFR/TP53 and EGFR/PIK3 CA gene co-mutation,but there is no statistically significant difference(P>0.05).The disease control rate(DCR)and objective response rate(ORR)of EGFR-TKIs in NSCLC patients with simple EGFR gene mutation were both higher than those with co-mutation of EGFR/TP53 and EGFR/PIK3CA,and the differences in the co-mutation DCR of EGFR/TP53 gene co-mutation were statistically significant(P=0.009),while the remaining were not statistically significant(P>0.05).Conclusion1.In the treatment of advanced NSCLC,multi-gene combination test is superior to single-gene test.2.EGFR ctDNA content was higher in young patients with higher detection sensitivity.3.TP53 gene mutations are correlated to the secondary EGFR T790M drug-resistant mutations in advanced NSCLC and the efficacy of EGFR-TKIs.4.In the EGFR/PIK3CA co-mutation,the PIK3CA/E545K mutation and T790M were secondary drug-resistant mutations.