Prevalence of EGFR mutations in non-small cell lung cancer (NSCLC) smoker patients.

Abstract

e21015 Background: Mutations in the Epidermal Growth Factor Receptor (EGFR) predict a better response to tyrosine kinase inhibitors compared to platinum-based chemotherapy in advanced non-small cell lung cancer (NSCLC). Previous studies in caucasian population have reported a frequency of EGFR mutation of 10-15%. The aim of this study is to analyze the prevalence of EGFR mutations in caucasian smoker patients with NSCLC. Methods: Prospective mutation testing in NSCLC patients included in our institution since October 2010 to January 2012 was performed on DNA obtained from available tumor tissue and cytologic samples, using ARMS-scorpion TheraScreen EGFR 29 Mutation Test Kit (Qiagen). Results: From 218 consecutive NSCLC diagnoses, 18 (8.25%) patients showed EGFR mutations: 6 (33.3%) exon 19 deletions, 9 (50%) exon 21 mutations (7 cases L858R and 2 cases L861Q) and 3 (16.6%) exon 20 insertions. In the EGFR-mutated patients, 13 (72.25%) were never-smoker and 5 (27.7%) were smoker (3 current-smoker and 2 former-smoker). The EGFR-mutated smoker population showed the following characteristics: 3 female, 2 male; 4 adenocarcinoma, one squamous cell carcinoma; 3 stage IV, 2 stage IA at diagnosis; 1 (20%) case EGFR deletion exon 19, 1 (20%) case insertion exon 20 and 3 patients (60%) mutation exon 21 (2, L858R and 1, L861Q). Conclusions: The EGFR mutation rate in NSCLC smoking patients in our referral area is superior (27.7%) than previously reported, reinforcing the importance of including EGFR mutation testing in NSCLC smoking population for the correct management of these patients.