Comparison Of Detecting EGFR Mutation Among Different Small Samples Of Advanced Lung Adenocarcinoma By Using ARMS Method

Background and objective: Targete drug of EGFR TKIs has been approved forpatients harboring EGFR mutations in NSCLC treatment,EGFR gene mutation can bescreened before appropriate patients accept the treatment of EGFR TKIs. The aim ofthis study is to investigate the prevalence of EGFR mutations in advanced lungadenocarcinoma of female patients and to analyze EGFR mutation differences amongDNA of fresh lung adenocarcinoma tissue,DNA in blood and DNA in malignantpleural effusion specimens.Then comparative anlysis of EGFR mutaion detectionrate,and assess the three kinds of small sample specimen which is more suitable forscreening patients before EGFR TKI therapy.Methods:We collected18cases of the fresh tumor tissue of lungenadenocarcinoma specimens of female patients，18cases of blood specimen of thesepatients and5cases of malignant pleural effusion included in these18patients.Weexamined lung adencarcinoma tissues, DNA in blood and malignant pleural effusionfrom18patients for EGFR mutations in exons18,19,20and21by using theamplification refractory mutation system(ARMS) method.The mutation differencesamongclinical character oflung adencarcinoma with EGFR mutation， bloodspecimens， malignant pleural effusion specimenswere compared by using theFisher’exact test.Results:18cases of fresh lung adencarcinoma tissues samples,10cases of bloodsamples （8cases were included in8positive mutation patients，2cases were innegative mutation patients）and5cases of malignant pleural effusion specimens （3cases were included in8positive mutation patients，others were in negative mutationpatients）were detected by ARMS method.The results showed that the rate of EGFRpositive mutation in fresh lung adencarcinoma tissues was44.4%(8/18)；comparedwith fresh lung adencarcinoma tissues,40%（2/5）in malignant pleural effusion and0in blood samples. There were positive mutations in8fresh lung adencarcinoma tissues samples, in which6cases were19Del,accouting of75%(6/8).3cases were21L858R,accouting of25%(2/8).There were also positive mutations in2cases ofmalignant pleural effusion specimens. They were all19Del,and100%(2/2) formalignant pleural effusion specimens,21L858R was not detected.Conclusion:1. Our results indicate that the EGFR mutation detected in the freshlung adencarcinoma tissues and in malignant pleuraleffusion is significantly higherthan that in the blood.2. It is more reliable that detecting EGFR gen mutation forsmall samples in lung adencarcinoma tissues and malignant pleural effusion by usingARMS method.