RESUMO
PURPOSE: To assess the frequencies of somatic EGFR mutations in the tumor tissues of patients with non-small cell lung cancer (NSCLC) residing in the South of Russia (SR), and to define the relationship between genetic subtypes of NSCLC and the emergence of different types of metastases. METHODS: DNA was extracted from formalin-fixed parrafin embedded (FFPE) samples of 721 patients. A total of 29 somatic EGFR mutations were detected using commercial Therascreen EGFR RGQ PCR Kit. RESULTS: EGFR mutations were significantly more frequent in females and non-smokers even when considering the combination of both factors. The frequency of activating EGFR mutations across three age groups (<51, 51-61, >61 years) of women with NSCLC was significantly different (x2=10.94, p=0.004) and became higher with increasing age. Both activating and resistance mutations of EGFR were not associated with the frequency of regional or distant metastases. The frequencies of both regional and distant metastases were associated with higher disease stage (odds ratio/OR)=16.71; 95% confidence interval (CI): 9.5-29.38; p<0.0001, and OR=2.94; 95% CI: 2.22-3.88; p<0.0001, respectively) and adenocarcinona histology (OR=6.52; 95% CI: 2.03-20.92; p=0.002, and OR=1.99; 95% CI: 0.91-4.34; p=0.083, respectively) even when adjusted for age, gender, and smoking status. The risk for regional metastases development was associated with poor tumor differentiation (OR=2.91; 95% CI: 1.21-7.02; p=0.017). CONCLUSION: EGFR mutations were not associated with the frequency of regional or distant metastases in SR patients with NSCLC.
