EGFR MUTATIONS IN NON-SMALL-CELL LUNG CANCERS: A SINGLE INSTITUTE EXPERIENCE

Background Mutations in the tyrosine kinase domain of EGFR in non-small-cell lung cancer (NSCLC) are predictive of response to EGFR-targeted therapy in advanced stages of disease. This study aimed to determine the frequency of EGFR mutations in NSCLCs and to correlate their presence with clinical characteristics. Methods In this retrospective study, EGFR mutations in exons 18, 19, 20, and 21 in formalin-fixed paraffin-embedded biopsy specimens of consecutive NSCLC patients were assessed by real-time PCR. The study was conducted over a period of 5 years from January 2009 to December 2013 in the Department of Medical Oncology in our institute. Findings EGFR mutations were detected in NSCLCs from 20 (25%) of 80 patients, being significantly more common in women (37.03%) than in men (18.8%) (odds ratio [OR] 0.39; 95% confidence interval [CI] 0.13–1.11; p  = 0.075) and in never smokers (42.85%) than in smokers and ex-smokers (11.11%) (OR 0.25, 95% CI 0.081–0.76; p  = 0.011). Mutations were more common in adenocarcinoma (32.07%) compared to non-adenocarcinoma NSCLCs (11.11%) (OR 3.7778; 95% CI 0.997–14.30; p  = 0.04). Interpretation In our patients with NSCLC, the EGFR mutation rate was similar to that in other Asian populations. EGFR mutations were significantly more common in female patients and in never smokers. Never smoking status of patients and adenocarcinoma histology were significant independent predictors for the presence of EGFR mutations.