Detection Of EGFRmutation In CfDNA Of Patients With Advanced NSCLC

Objective:Toexplore the feasibility of testing EGFR mutation in cf DNA of patients with advanced NSCLC.Methods: A total of 80 pairs of tissue and plasma samples before treatment were collected。The DNA of both samples were extracted by adsorption column and the EGFR mutation status of each sample was analyzed by Amplification Refractory Mutation System(ARMS).We analyzed the sensitivity,specificity and coincidence rate of EGFR mutations in cf DNA in compared with tissue.Results:The mutation rate of EGFR gene in 80 cases of tumor tissue / cell samples was 53.8%(43/80),and the mutation rate of cfdna EGFR gene in peripheral blood samples was(30/80).30 cases of peripheral blood test results for the positive cases,the corresponding tumor tissue / cell detection results are positive and consistent type of mutation,peripheral blood plasma detection sensitivity was 69.8%(30/43),positive predictive value of 100%(30/30).37 cases of tumor tissue / cell samples were negative,the detection results were negative for peripheral blood,peripheral blood plasma detection specificity was 100%(37/37),negative predictive value was 74%(37/50).Of the 80 paired samples,67 presented the same EGFR mutation statuses in the tissues and plasmaand,the concordance rate was 83.8%(67/80).The EGFR mutation rate and clinical features showed some correlation: 68.8% women than men(22/32)43.8%(21/48)(P< 0.05),66.7%(26/39)than not smoking smoking 41.5%(17/41)(P< 0.05),adenocarcinoma(41/70 58.6%)than non adenocarcinoma in 20%(2/10)(P< 0.05),had no statistical significance with age(P> 0.05).Conclusions:1.The detection of EGFR gene mutation in peripheral blood plasma by cfdna arms has a high sensitivity and high specificity,and has a high concordance rate with the detection of EGFR mutation in tumor tissue / cell samples;2.For patients with advanced non-small cell lung cancer,who are unable to obtain adequate tumor tissue / cell samples,peripheral blood is a new source of EGFR gene mutations;3.There was a certain correlation between EGFR mutation and clinical features,and the mutation rate of female,non-smoking and adenocarcinoma patients was significantly higher than that of male,smoking and non adenocarcinoma patients.