ABSTRACT
Purpose To investigate the prevalence of EG-FR mutation in circulating cell-free DNA in non-small cell lung cancer (NSCLC) patients of Yunnan province and its relationship with clinical pathological characteristics,which can provide foundations for individualized targeted therapy of lung cancer in this area.Methods Amplification refractory mutation system (ARMS) was used to detect the EGFR exon 18,19,20 and 21 mutation in circulating cell-free DNA.The relationship between EGFR mutation and clinical characteristics were further analyzed.Results 93 patients (25.5％) harbored circulating EG-FR mutations among 364 patients.The mutation rates of EGFR 18 G719X,19del,20 S768I,T790M,20ins were 3.2％ (3/93),2.2％ (2/93)and3.2％ (3/93)respectively.EGFR21 L858R and L861Q mutation rates were 26.9％ (25/93) and 1.1％ (1/93),respectively.Three patients (3.2％,3/93)harbored G719X + S768I double mutation,four patients (4.3％,4/93) harbored 19Del + T790M mutations.19Del +L858R,L858R + S768I,and S768I + T790M mutation rates were 1.1％ (1/93),1.1％ (1/93) and 2.2％ (2/93) respectively.Conclusion The EGFR mutation rate of female and adenocarcinoma patients is higher in patients with stage Ⅲ B-ⅣNSCLC in Yunnan area.19Del is the major mutation type and double exon mutation is an obvious characteristic in NSCLC patients of Yunnan province.EGFR mutation detection in circulating cell-free DNA by ARMS method is feasible to screen patients receiving EGFR-TKIs treatment.