Analysis Of Sensitivity And Influence Factors Of EGFR Next-generation Sequencing In Peripheral Blood Of Nonsmall Cell Lung Cancer Patients

Objective : on the basis of the next generation sequencing(NGS)technology,to explore the feasibility and sensitivity of detecting EGFR Gene in Peripheral Blood of NSCLC,and to further analyze the related factors affecting its sensitivity.Methods : The tumor tissue specimens of NSCLC patients diagnosed in the Department of Pathology of the first affiliated Hospital of Soochow university from January 2015 to May 2017 were collected,the peripheral blood samples were collected at the same time.The Illumina Hi Seq 2000 high throughput sequencing platform(NGS)was used to detect EGFR genes in two groups of samples.1.To collect the general clinical data of patients and compare the mutation of EGFR gene in peripheral blood and tumor tissues.Calculation of sensitivity and consistency of peripheral blood test results by formula.The relationship between mutation of EGFR gene and clinical features was analyzed by X2-test.2.Taking the results of tumor tissue detection as the gold standard,the influence of sex,age,smoking history,pathological type,clinical stage,pathological differentiation,chemotherapy history of lung cancer,mutation abundance of EGFR gene in tumor tissue on the detection sensitivity of EGFR gene in peripheral blood were analyzed by X2-test.The independent influencing factors were further analyzed by multivariate Logistc regression.At the same time,the ROC curve was used to analyze the mutation abundance of EGFR gene in tumor tissues.Results:1.A total of 187 paired specimens were collected in this paper,by comparing the mutation of EGFR gene between peripheral blood and tumor tissue,we found that the specificity of peripheral blood detection is 99.1%,and the EGFR mutation site were basically the same in 44 cases of mutation detected at the same time in the two groups,therefore,the results of peripheral blood detection are reliable.2.The formula calculation results are,the sensitivity of peripheral blood detection is62.0%,the specificity is 99.1%,the consistent rate of two groups is 85.0%;It is feasible to use peripheral blood as a sample for detection.Mc Nemar test showed that the detection rate of tumor tissue mutation was significantly higher than that of peripheral blood,as a testing specimen,the peripheral blood is inferior to tumor tissue.The consistent of Kappa when test two the groups showed that the mutation status of EGFR gene in tumor tissues and peripheral blood was generally consistent.3.Taking the results of tumor tissue detection as the gold standard,we found that in clinical features,sex,smoking history and tumor pathological type were correlated with EGFR gene mutation.That is,women,non-smoking and adenocarcinoma patients are the dominant population for EGFR gene detection.4.In clinical stage,N stage and M stage,pathological differentiation degree,history of lung cancer chemotherapy,gene mutation abundance of tumor tissue had great influence on the sensitivity of peripheral blood EGFR gene detection.However,sex,age,smoking history,pathological type and T stage in clinical stage had no significant influence on the sensitivity of the detection.Among of which,clinical stage,pathological differentiation degree,the history of lung cancer chemotherapy and the mutation abundance of tumor tissue were independent factors,and the ROC curve analysis showed that when the EGFR gene mutation was more than 24% in tumor tissue,the sensitivity of peripheral blood detection was significantly higher.Conclusion:The results of EGFR gene detection in peripheral blood are reliable,with a high sensitivity and high specificity,leading to a certain clinical guiding value and is an effective supplement for histologic gene detection.For patients who could not obtain histological specimens for various reasons,peripheral blood could replace histological specimens for gene detection.Female,non-smoking and adenocarcinoma patients are the dominant group for EGFR gene detection.Detection of EGFR gene in peripheral blood of patients with advanced stage,low differentiation,no history of lung cancer chemotherapy,mutation abundance of EGFR gene in tumor tissue > 24% can obtain higher sensitivity.