P3.01-33 EGFR Mutation in Patients with NSCLC and Its Relationship Between Survival and Clinicopathological Features: An Update Analysis

There have been important developments in NSCLC since the understanding of molecular pathways. The aim of the study is to find the EGFR mutation frequency and its correlation to survival and clinicopathological features. We reported our data in this subject three years ago. We aim to resubmit our updated data. In this multicenter study, 1352 NSCLC (adenocarcinoma) patients were included retrospectively to find out the EGFR mutation status with age, sex, performance status, histopathological diagnosis, smoking status and stage. Survival correlates were determined. The aim of the study was to find out the EGFR mutation status with all of the features in the database. The median age was 59 (24-87) years. Median follow-up time was 14 (2-117) months. 26,2 % were female. 85,2% were stage IIIB-IV and 86 % was adenocarcinoma. EGFR mutation frequency was 22,3 % including exon 19 (63,0%). There was no correlation between mutational status and age, performance status, and stage at diagnosis (p>0,05). However, there was a correlation between gender and, smoking.. (p= 0.000 and 0,000. respectively). The frequency of mutation in female patients was more pronounced in non-smokers/ex-smokers. In the group that can perform survival analysis (827 pts), median progression-free survival was 9 months and overall survival was 20 months. The overall survival was 27 (SE:5; 95% CI 17-36) months in EGFR positive cases whereas 19 (SE:1; 95% CI 16-21) months in EGFR negative cases (p=0,008). The multivariate analysis showed good performance status, early stage disease and presence of EGFR mutation as a prognostic factor (p<0,05). Our investigation shows that the EGFR mutation rate in our patient population with adenocarcinoma of the lung was higher than in Western countries population and was lower than the East Asian population. The determination of EGFR mutation will lead the pathway for a better treatment outcome and individualized therapy.