EGFR gene mutation analysis among 185 cases of NSCLC patients in south of China

Objective To investigate the characteristics of EGFR gene mutations among NSCLC patients in south of China and analyze the correlation between mutations and clinical features.Methods Specimens of lung cancer tissues were collected from 185 NSCIC patients in our hospital.DNA was extracted from specimens.Exon 18,19,20 and 21 of EGFR gene were amplified by FQ-PCR to be bi-directional sequenced.Results EGFR gene mutations in 62 (33.5％) of 185 NSCLC patients was identified in carcinoma tissues,of which,2cases,41cases,5 cases and 14 cases respectively located at exon 18,exon 19,exon 20 and exon 21.The mutation of Del L747 → P752 (P753S) ( proportion 8.1％ ),Del E746 → A750 ( proportion 45.1％ ) at exon 19 and L858R ( proportion 22.6％ ) at exon 21 were the predominant mutation in 16 kinds of mutations.Four cases of mutation at exon 19 got the different results in bi-directional sequencing.The silent mutation 2361G →A at exon 20 was observed (28.1％ ).The mutation rate in women was significantly higher than men (46.2％ vs 24.3％,x2 =9.670,P =0.002).Non-smokers had significantly higher mutation rate than smokers (41.4％ vs 17.1％,x2 =7.380,P =0.007) ; Adenocarcinoma patients had significantly higher mutation rate than squamous cell carcinoma (38.3％ vs 6.3％,x2 =6.426,P =0.011).Clinical stage Ⅲ patients had significantly lower mutation ratethan patients with stage Ⅱ or Ⅳ ( 10.8％ vs 53.8％,x2 =8.026,P =0.003 ;10.8％ vs 41.3％,x2 =9.518,P =0.002).No statistically significance correlation was found between the mutation ratio and age.Conclusions EGFR gene mutation has a close relationship with females,non-smokers and adenocarcinoma.Most mutations occur in exon 19 and 20 among patients in south of China. Key words: Carcinoma, non-small-cell lung/genetics;  Receptor, epidermal growth factor/genetics;  Mutation