| Objective: 117 patients with advanced non-squamous non-small cell lung cancer were detected by NGS to identify the differences of molecular typing,including common and rare mutation types and mutation sites,and were dynamically monitored of ctDNA,the results of NGS were combined with clinical data and clinical treatment effect,so as to comprehensively evaluate the role of NGS technology in clinical guidance.Methods: 117 patients with advanced non-squamous non-small cell lung cancer who visited the second hospital of Dalian Medical University from January 2017 to December 2018 and met the inclusion criteria were collected.Tumor tissues,blood,body fluids and other samples of patients at different stages were collected,sequenced by high-throughput Illumina sequencing method,bioinformatics analysis was conducted to obtain variation information.A total of 104 enrolled patients were newly treated without targeted therapy,and were detected by NGS to identify their pre-treatment molecular typing;among them,14 patients were tested again wnen they were resistant to first-generation EGFR TKIs after enrollment,with the remaining 13 patients who were resistant to first-generation EGFR TKIs at the time of enrolled,there were a total of 27 patients were detected by NGS to identify their molecular typing after drug resistance.The results of NGS combined with clinical data and clinical treatment effect were analyzed retrospectively,and IBM SPSS Statistics 22.0 was used for statistical analysis.Results: 1.A total of 463 tumor-specific mutation sites were detected in 104 newly treated patients,involving 165 genes in total,with 3 median mutations and 59% missense mutations.There were 73 common driver mutation sites in NSCLC,and 0.7 driver mutation site was detected in each patient on average.It suggests that NGS technology can detect more mutation sites.2.The common driver gene mutations and their probabilities in 104 newly treated patients were EGFR 45%(47/104),ALK 7%(7/104),ERBB2 4%(4/104),BRAF 3%(3/104),MET 1%(1/104),ROS1 2%(2/104),RET 1%(1/104),respectively.There were 47 cases of EGFR mutation,including 25 cases of L858 R mutation,11 cases of 19 DEL mutation,1 case of L861 Q mutation,1 case of A767 delinsASVD mutation,and 1 case of L747 S mutation.8 cases were double mutations of EGFR,the genotypes were L858R+T790M,G719A+T790M,G719A+E709K,G719S+E709A,S768I+V769L,G719S+S768I,G719A+H773L,G719S+R776H.It suggests that NGS technology can detect more EGFR mutation forms.3.27 patients with first-generation EGFR TKIs resistance underwent NGS detection,and the results showed that 52%(14/27)of the patients detected T790 M mutations,all the 14 patients were accompanied by 19 DEL or L858 R sensitive mutations,and 3 patients were accompanied by EGFR gene amplification.48%(13/27)of the patients had a negative mutation of T790 M,six patients were detected with EGFR common sensive mutation,two with L861 Q mutation,which were associated with NF1,PIK3 CA mutation and ERBB2 gene amplification,respectively.The other 4 cases were 2 cases of L858 R and 2 cases of 19 DEL mutation,respectively.1 of the 4 patients newly occurred TP53 mutation,compared with the result of the patient treated before,and 1 patient occurred BRAF L597 Q mutation.Among the remaining 7 patients,ERBB4 and TP53 mutations were detected in 2 patients respectively,and no specific gene mutation was detected in the other 5 patients.It suggests that NGS technology can help clarify the mechanism of drug resistance.4.In the 47 patients with EGFR mutation,35 cases were targeted therapied with first-generation EGFR TKIs,and by the end of follow-up,27 cases were PD,8 cases were still effective,and the mPFS was 10 months(95%CI 8.123-11.877).According to whether tumor suppressor genes such as TP53 and RB1 are combined or driving genes such as BRAF and ERBB2 are combined,they are divided into EGFR mutation only(13/35)and EGFR concomitant with other gene mutations(22/35),Kaplan-meier method was used to draw the survival curve,and Log Rank was used to test the statistical difference of the two groups.The results showed that: mPFS was 14 months vs 8 months(P=0.002),so the survival curve of the two group was significantly different,the EGFR mutant alone was more effective with TKIs than those with other genetic mutations.5.Among the 7 patients with ALK fusion mutation,4 patients were ELM4-ALK fusion mutation and 3 patients were rare ALK fusion mutation with NCK2-ALK,PKNOX2-ALK and IGR-ALK,respectively.They were benefit from targeted treatment with crizotinib.At the end of follow-up,the treatment was still effective in 3 patients with rare fusion.The PFS1 of the patient with NCK2-ALK fusion treated with single crizotinib was 14 months,and the combination of chemotherapy was still effective after the progression.The current PFS2 was 8 months,and the cumulative effective time was 22 months,the remaining 2 patients currently had PFS of 5 months and 1 month,respectively.It suggests that NGS technology can detect the more rare ALK fusion forms.6.16 patients received plasma ctDNA dynamic monitoring using NGS and RECIST clinical efficacy evaluation every 6-8 weeks.During the dynamic monitoring,10 patients presented increasing ctDNA mutation abundance or new genes,and 6 patients who received RECIST clinical efficacy evaluation were PD.It suggests that the dynamic monitoring of ctDNA by NGS technique may indicate clinical drug resistance.7.6 patients with meningeal metastasis underwent NGS detection of paired cerebrospinal fluid and peripheral blood ctDNA,and EGFR-sensitive mutations were detected in 4 patients.The mutation abundance of cerebrospinal fluid ranged from 22.2% to 47.9%,while that of peripheral blood ranged from 0 to 0.2%.All 4 patients benefited from Osimertinib,and the treatment was still effective at the end of follow-up,and the current PFS was 3-8 months.It suggests that the detection of cerebrospinal fluid by NGS in patients with meningeal metastasis was more significant than that of peripheral blood.Conclusion: 1.The application of NGS tissue and liquid biopsy technology can detect multiple common,rare and multiple gene complex mutations and more types of mutations in lung cancer,and the molecular resistance mechanism of EGFR TKIs can be found through NGS liquid biopsy technology,which was beneficial to guide the accurate treatment of advanced NSCLC.2.Dynamic monitoring of ctDNA revealed that when the gene mutation abundance increased or new genes appeared,it may indicate clinical drug resistance.3.For patients with meningeal metastasis,NGS detection of cerebrospinal fluid was more significant than that of peripheral blood. |
PDF Full Text Request