Epidermal Growth Factor Receptor Mutational Status and Brain Metastases in Non–Small-Cell Lung Cancer

Abstract

Introduction: Epidermal growth factor receptor (EGFR) mutations in non–small-cell lung cancers (NSCLC) may be more common in patients with brain metastases. Previous studies, however, did not adjust for effects of confounding variables. Methods: This retrospective study included 1,522 consecutive patients with NSCLC, whose tumors were diagnosed and tested for EGFR mutations at the University of Nebraska Medical Center (Omaha, NE) and Tata Memorial Hospital (Mumbai, India). Multivariate logistic regression was used to identify any association between EGFR status and clinical factors. Results: EGFR mutations were more common in females than males (38.7% v 24.8%), Asians than whites (31.3% v 13.4%), nonsmokers than smokers (40.2% v 14.6%), alcohol nonconsumers than users (32.4% v 15.8%), adenocarcinoma than other histology types (32.7% v 10.3%), and patients with brain metastases than extracranial or no metastases (39.4% v 29.8% v 15.1%; P < .001 for all comparisons). There was a higher likelihood of an EGFR mutation among patients with brain metastases (odds ratio, 1.8; P < .001). The median overall survival (OS) was 19.8 months. Patients with brain metastases had a shorter median OS (15 v 20.6 months; P = .02). However, in the cohort of EGFR mutation–positive patients, there was no difference in median OS between patients with and without brain metastases (20.8 v 25.1 months; P = .11). Conclusion: There is a nearly two-fold higher incidence of EGFR mutations in NSCLC among patients with brain metastases at diagnosis. EGFR mutations did not predict for outcomes from brain metastases.