Study On EGFR Mutation Status In Pleural Effusion And Tumor Tissue Of Patients With Advanced Lung Adenocarcinoma

Objective: To analyze and compare the mutation of EGFR gene in pleural effusion and tumor tissues of patients with advanced lung adenocarcinoma,to explore the relationship between EGFR gene mutation and clinical characteristics of patients,and to explore the clinical feasibility of detecting EGFR gene mutation with pleural effusion.Methods: From May 2017 to July 2018,60 samples of pleural effusion and 80 samples of tumor tissue were collected from patients with advanced lung adenocarcinoma diagnosed in the department of oncology of Inner Mongolia People's Hospital,including 46 cases of paired tumor tissue and pleural effusion.The EGFR gene mutations in tumor tissues and pleural effusion were detected by amplification refractory mutation system PCR(ARMS-PCR).Using SPSS 20.0 statistical software for experimental data analysis,Chi-square test was used to analyze the relationship between EGFR gene mutation in tissues and clinical characteristics of patients and to compare the difference of EGFR gene mutation rate between pleural effusion and corresponding tumors,The consistency test was used to analyze the consistency of EGFR gene mutations among paired samples.The difference was statistically significant at P < 0.05.Results:(1)The mutation rate of EGFR gene in female patients was significantly higher than that in male patients(P=0.013);The mutation rate of EGFR gene in non-smokers was significantly higher than that in smokers(P=0.002);There was no significant difference in the mutation rate of EGFR gene among patients of different age groups(P=0.146),and there was no significant difference in the mutation rate of EGFR gene among tumor tissue obtained by different methods(P=0.622).(2)The mutation rate of EGFR gene in pleural effusion samples was 46.67%(28/60),thepercentage of 19-del mutation,L858 R mutation and rare mutation in the total mutation were 46.43%(13/28),42.86%(12/28)and 10.71%(3/28),respectively.(3)The mutation rate of EGFR gene in tumor tissue samples was 51.25%(41/80),the percentage of 19-del mutation,L858 R mutation and rare mutation in the total mutation were 53.66%(22/41),41.46%(17/41)and 4.88%(2/41),respectively.(4)There was no significant difference in mutation rate of EGFR gene between pleural effusion and corresponding tumor tissue(P=0.532);and there were 39 pairs of paired samples with the same results of gene mutation detection,the consistency rate of EGFR gene mutation in paired samples was 84.78%(39/46),the Kappa value of consistency between the two groups was 0.697,and the level of consistency was good(P<0.001).Conclusions:(1)Female and non-smoking patients with lung adenocarcinoma are at high risk for EGFR gene mutation,there was no significant correlation between EGFR gene mutation and age or the way of obtaining tumor tissue.(2)The main mutation types of EGFR gene in pleural effusion and tumor tissues of patients with advanced lung adenocarcinoma were 19-del mutation and L858 R mutation.(3)EGFR gene mutation in pleural effusion of patients with advanced lung adenocarcinoma has good consistency with the corresponding tumor tissues,it is feasible to detect EGFR gene mutation with pleural effusion.When it is difficult to obtain tumor tissue,it is recommended to use malignant pleural effusion instead of tumor tissues to detect EGFR gene mutation in order to provide reliable clinical basis for the selection of individualized targeted therapy for advanced lung adenocarcinoma patients.