Analyses Of EGFR And K-ras Gene Mutations In NSCLC Patients With Initial Treatment

Objective To analyze the EGFR and K-ras gene mutations of NSCLC patients with initial treatment, and to provide references for clinical medication of TKIs.Methods The pathological tissue samples of93NSCLC patients with initial treatment were collected from the affiliated hospitals of central south university. DNA were extracted from each sample and were amplified by polymerase chain reaction. Using pyrosequencing to detect the mutation status of exons19,20and21of EGFR gene and the codons12and13of exon2of K-ras gene, and analyze the relationship between the mutation status and clinical pathological features.Results In these93patients, the mutation rates of EGFR gene were24.7%(23/93), and the mutation rates of exons19,20and21were56.5%(13/23),8.7%(2/23) and39.1%(9/23) of EGFR gene respectively,(one case with both exons19and20mutated). The mutation rates of K-ras gene were6.5%(6/93), and the mutation rates of codons12and13were66.7%(4/6) and50.0%(3/6), respectively,(one case with both codons12and13mutated). Both EGFR and K-ras gene mutations in one patient was not detected. Compared with males, smokers, non-adenocarcinomas and stage Ⅲb-Ⅳ patients, the mutation rates of EGFR gene for TKIs sensitivity were higher in those females, non-smokers, adenocarcinomas and stage Ⅱ-Ⅲa patients, and the mutation rates were9.8%(6/61) vs46.9%(15/32),8.5%(5/59) vs47.1%(16/34),8.1%(3/37) vs32.1%(18/56) and16.9%(11/65) vs35.7%(10/28), respectively. The K-ras gene’s mutation rates of patients whose PS scores>2were higher than those whose PS scores were0-1points, which were16.1%(5/31) vs1.6%(1/62), and had significant difference (P<0.05).Conclusions1、There are22.6%of NSCLC patients with initial treatment have mutations of EGFR gene for TKIs sensitivity, among which the mutations of exons19and21are mainly accounted, and the mutations mostly find in females, non-smokers and adenocarcinomas.2、There are6.5%of NSCLC patients with initial treatment have mutations in K-ras gene, among which the mutations of codon12are mainly accounted, and the mutations are more revealed in patients whose PS scores>2.3、There are2%of NSCLC patients with initial treatment have mutations in exon20of EGFR gene for TKIs resistance.