| PART ⅠAbstract:Objective To explore the clinical application value of Super-ARMS method in detecting epidermal growth factor receptor(EGFR)gene mutations in circulating tumor DNA in peripheral blood samples of lung adenocarcinoma patients.Methods A total of 307 patients with lung adenocarcinoma diagnosed in Beijing Chest Hospital from January 2019 to June 2020 were collected.EGFR gene mutations in tumor tissues were detected by mutation amplification system(ARMS),and EGFR gene mutations in plasma were detected by Super-ARMS.A total of 108 patients underwent tissue and peripheral blood EGFR gene testing at admission without treatment.Of the 153 patients with disease progression who underwent re-biopsy,74 received tissue re-biopsy and 141 received liquid re-biopsy,of which 62 received both tissue and liquid re-biopsies.Progression-free survival(PFS)of patients with EGFR T790M gene mutation detected by different techniques was compared by survival analysis.Results The tissue test results were taken as the gold standard.Among 108 patients,the sensitivity and specificity of blood Super-ARMS were 71.2%,92.9%,and the coincidence rate of tissue test was 79.6%.After the progress of drug resistance,74 patients underwent tissue re-biopsy,and 34 patients(45.9%)were found EGFR T790M gene mutation in tumor tissue samples.The EGFR T790M gene mutation in peripheral blood ctDNA was detected in 51 cases(36.2%)of 141 patients.Kaplan-Meier survival analysis showed a median PFS of 16.3 months(95%CI:7.5-25.2 months)for tissue EGFR T790M mutation positive patients and 11.4 months(95%CI:7.0-15.8 months)for peripheral blood EGFR T790M mutation positive patients,with no statistically significant difference(χ2=1.138,P>0.05),with a median PFS of 8.3 months(95%CI:5.8-10.8 months)for patients with T790M negative rebiopsy and not receiving third-generation EGFR-TKI therapy.The differences among the three groups were statistically significant(χ2=9.69,P<0.05).The median PFS of patients with tissue EGFR T790M mutation negative who did not receive the third generation of EGFR-TKIs was 7.0 months(95%CI:6.0-8.0 months),and that of patients with peripheral blood EGFR T790M mutation negative who did not receive the third generation of EGFR-TKIs was 7.0 months(95%CI:4.4-9.6 months),with no statistically significant difference(x2=0.47,P>0.05).Conclusion In the real world,the detection of peripheral blood samples by Super-ARMS method is expected to be applied to detect EGFR-sensitive mutations and T790M gene mutations.The peripheral blood samples can supplement the tissue samples to a certain extent to detect EGFR gene mutations,and predict the efficacy of patients with the thirdgeneration EGFR-TKI.Part ⅡAbstract:Objective To explore the feasibility of detecting EGFR mutation by ctDNA extracted from bronchoalveolar lavage fluid,and to compare it with tissue samples and blood samples of lung adenocarcinoma patients.To explore the relationship between gene mutation status of BALF ctDNA Epidermal growth factor receptor(EGFR)and clinical characteristics,so as to provide diagnosis for clinical targeted therapy.Methods Forty-nine patients with NSCLC who were first admitted to Beijing Chest Hospital of Capital Medical University from November 2019 to January 2021 were included.BALF and tissue samples of 49 patients and peripheral blood samples of 26 patients were collected.EGFR gene mutations in BALF and peripheral blood were detected by Super-ARMS technique,and tissue samples were detected by NGS method.SPSS25.0 statistical software was used for data analysis.Results There were no differences in EGFR mutation status in age,smoking status,clinical stage,pleural effusion or not,and clinical classification in BALF samples,but statistically significant differences were found in gender(P=0.038).Using the tissue test results as the gold standard,there were 26 cases of tissue matching with plasma and BALF,19 cases of plasma were consistent with the mutation type detected in the tissue,and 7 cases of samples had EGFR mutation detected in the tissue,but no mutation detected in the blood.In four samples,EGFR mutations were detected in BALF but not in the blood.The calculated sensitivity,specificity and coincidence rate of peripheral blood ctDNA for detection of EGFR mutations were 61.1%,100%and 73.1%.According to the consistency analysis and evaluation of the diagnostic experiment,Kappa between peripheral blood and tissue was 0.492,and that between peripheral blood and Balf Kappa was 0.62.In other words,the consistency of EGFR gene mutation in peripheral blood and tissue detection was moderate,and the consistency of EGFR gene mutation in peripheral blood and BALF detection was good.There were 49 cases of tissue NGS matching with BALF,22 cases of EGFR mutation detected in BALF,of which 41 cases were consistent with the results of tissue detection,and 8 cases of samples showed EGFR mutation detected in tissues,while no mutation was detected in BALF.The calculated sensitivity,specificity,coincidence rate,false positive rate=0%,false negative rate=26.7%,positive predictive value=100%,negative predictive value=70.4%for BALF ctDNA in the detection of EGFR mutations.According to the consistency analysis and evaluation of the diagnostic experiment,the Kappa value was 0.681,that is,BALF detection of EGFR gene mutation and tissue detection of EGFR gene mutation had a good coincidence,and the two detection methods had a certain consistency.Conclusion There was no significant difference in age,smoking status,clinical stage,pleural effusion and clinical classification between BALF ctDNA of EGFR gene mutant group and wild-type group(P>0.05);The gender difference was statistically significant(P<0.05).The detection of BALF samples by Super-ARMS is expected to be applied to detect EGFR gene mutations.BALF samples can supplement tissue samples and peripheral blood samples to a certain extent to detect EGFR gene mutations,especially in female patients. |
PDF Full Text Request