Analysis Of Gene Mutation Phenotype And Clinicopathological Features Of Non-small Cell Lung Cancer Based On Next Generation Sequencing

Background and purposeStudies have shown that common driver gene mutations in non-small cell lung cancer often exist independently,with the application of next-generation sequencing technology,more and more complex mutations have been discovered.This study used next-generation sequencing technology to detect the mutant phenotypes of EGFR,KRAS,BRAF,ALK,ROS1,RET,MET,and HER2 genes in non-small cell lung cancer,analysis the correlation between mutations and clinicopathological features,exploring the correlation between these gene mutations.Methods1 The clinical and pathological data of 1051 cases with NSCLC diagnosed by the Department of Pathology,First Affiliated Hospital of Zhengzhou University from January 1,2017 to March 1,2018 were collected.2 The paraffin-embedded tissues of 1051 NSCLC cases(801 biopsy specimens,210 surgical specimens,and 40 cell masses)were detected by next-generation sequencing technology,detection of point mutations,insertions,deletions,gene fusions or copy number variations of 8-180 genes including EGFR,KRAS,BRAF,ALK,ROS1,RET,MET,HER2 genes.3 Data analysis using SPSS 23.0 statistical software,correlation between gene mutations and clinicopathological features of NSCLC using Pearson's chi-square test or Fisher exact probability method,correlation between mutations of various genes using Spearman rank correlation,the test level ?=0.05,using a significant level of bilateral test,P<0.05 was considered statistically significant.Results1 Mutation rate of each geneIn 1051 NSCLC cases,the overall mutation rate of the gene was about 74.22%(780/1051).The mutation rates of EGFR,KRAS,BRAF,ALK,ROS1,RET,MET,and HER-2 genes were 49.57%(521/1051),10.09%(106/1051),3.52%(37/1051),and 8.56%(90/1051),2.57%(27/1051),2.19%(23/1051),3.90(41/1051),0.76%(8/1051)respectively.2 Correlation between gene mutation phenotype and clinicopathological feature2.1 EGFR gene mutation was associated with gender,age,smoking history,pathological type(P<0.05),and had no correlation with cTNM staging(P>0.05).2.2 KRAS gene mutation was associated with gender,age,and smoking history(P<0.05),and had no correlation with pathological type and cTNM stage(P>0.05).2.3 There was a correlation between BRAF gene mutation and clinical pathological type(P<0.05),but no correlation with gender,age,smoking history and cTNM stage(P>0.05).2.4 The ALK gene mutation was associated with gender,age,smoking history and tumor cTNM stage(P<0.05),but had no correlation with tumor pathological type(P>0.05).2.5 There was a correlation between ROS1 gene mutation and age,cTNM stage(P<0.05),but no correlation with gender,smoking history and pathological type(P>0.05).2.6 There was no correlation between RET,MET,and HER2 gene mutations in gender,age,smoking history,pathological type,and cTNM stage.3 Difference between single mutation and complex mutation in clinicopathological characteristics3.1 There was significant difference in clinical stage between EGFR complex mutation and single mutation(P<0.05).There were significant differences in sex and smoking history between ALK complex mutation and single mutation(P<0.05).3.2 There was no significant difference between KRAS,BRAF,ROS1,RET,MET gene complex mutation and single mutation in sex,age,smoking history,pathological type and cTNM stage(P>0.05).4 Correlation between mutations of each gene4.1 Mutations in EGFR gene were negatively correlated with KRAS,BRAF,ALK,ROS1,and RET gene mutations(P<0.05),and were not associated with MET gene mutation(P>0.05).4.2 KRAS gene mutation was associated with EGFR gene mutation(P<0.05),and there was no correlation with ALK,ROS1,RET,MET,BRAF gene mutations(P>0.05).4.3 There was a correlation between BRAF,EGFR and RET gene mutations(P<0.05),which was not related to KRAS,ALK,ROS1 and MET gene mutations(P>0.05).4.4 There was a correlation between ALK gene mutation and EGFR gene mutation(P<0.05),and no correlation with KRAS,BRAF,ROS1,RET and MET gene mutations(P>0.05).4.5 There was a correlation between ROS1 gene mutation and EGFR gene mutation(P<0.05),and no correlation with KRAS,BRAF,ALK,RET and MET(P>0.05).4.6 There was a correlation between RET gene mutation and EGFR,BRAF gene mutations(P<0.05),but no correlation with KRAS,ALK,ROS1,MET gene mutations(P>0.05).4.7 There was no correlation between MET gene mutation and EGFR,KRAS,ALK,ROS1,RET and BRAF gene mutations(P>0.05).5 First discovered single gene mutation phenotype5.1 A case of EGFR-CLP2 gene fusion.A case of EGFR 21 exon L858 R point mutation combined with LINCO1446-EGFR(E5:E25)gene fusion.A case of EGFR gene exon 19 deletion mutation combined with EGFR-FLJ45974 & HPVC1 gene fusion and EGFR gene copy number amplification.5.2 A case of S174 L mutation in exon 4 of KRAS gene.5.3 A case of deletion of mutation of exon 12 of BRAF gene.5.4 A case of ALK-C2orf91 gene fusion.5.5 A case of ROS1-MYH9 gene fusion.A case of CD74-ROS1 combined with SLC34A2-ROS1 gene fusion.A case of CD74-ROS1 combined with RND/NR110241-CD74 gene fusion.5.6 A case of RET-NCOA4 gene fusion.5.7 A case of MET gene amplification combined with MET-ZFHX4 gene fusion.A case of MET amplification combined with FGFR3-TACC3 gene fusion.6 First discovered multi-gene coexisting mutation6.1 A case of EGFR gene exon 3 Gln83 Leu mutation combined with LOC101927577-ALK gene fusion.6.2 A case of EGFR gene 19 exon deletion mutation combined with BCL2L11 exon 2 deletion mutation.6.3 A case of EGFR gene 20 exon insertion mutation combined with BRAF gene TRBV4-BRAF gene fusion.6.4 A case of EGFR gene 21 exon L858 R mutation combined with FANCE-ALK gene fusion,ERC1-ROS1 gene fusion and MET gene copy number amplification.6.5 A case of KRAS gene copy number amplification combined with EML4-ALK,LINCO1250-ALK gene fusion and MET gene copy number deletion.6.6 A case of BRAF gene exon 1 AsP22 Asn missense mutation combined with RET gene CCDC6-RET gene fusion.6.7 A case of EML4-ALK combined with BCL2L11 exon 2 c.394+1479-+4381del deletion mutation.Conclusions1 Driving gene mutations can coexist in non-small cell lung cancer,and there is a correlation between the driving gene mutations.2 Most of the EGFR gene mutations in patients with advanced non-small cell lung cancer are complex.