EGFR Gene Alterations in a Norwegian Cohort of Lung Cancer Patients Selected for Surgery

Introduction: Lung cancer is the leading cause of cancer-related deaths worldwide. New therapies targeting the epidermal growth factor receptor (EGFR) tyrosine kinase are promising and show high response rates in the subset of patients with activating mutations in EGFR. The frequency of these mutations is largely unknown in unselected Caucasian patients. Methods: Mutation analysis of EGFR exons 18-21 was performed on 240 lung cancer samples using the TheraScreen EGFR mutation kit and denaturing high-performance liquid chromatography in addition to sequencing. Results: In a cohort of 240 Norwegian lung cancer patients selected for surgery, we identified 18 tumors with EGFR-activating mutations (7.5%, 14 women and 4 men), of which 14 were adenocarcinomas, 2 squamous cell carcinomas, and 2 bronchoalveolar carcinomas. Five of the mutations were found in patients with more than 20 pack-years of smoking history. Conclusion: The frequency of EGFR mutations is lower in our cohort than among Asian lung cancer patients and present in both men and women and smokers and never-smokers. However, the frequency is significantly higher among women and never-smokers and among patients with adenocarcinomas.