Clinical Features and Outcome of Patients With Non–Small-Cell Lung Cancer Harboring BRAF Mutations

Abstract

Purpose To investigate the prevalence, distribution, and prognostic role of BRAF mutations in a large cohort of white patients with non–small-cell lung cancer (NSCLC). Patients and Methods A retrospective series of 1,046 NSCLCs—comprising 739 adenocarcinomas (ADCs) and 307 squamous cell carcinomas (SCCs)—was investigated for BRAF mutations. High-resolution melting analysis followed by sequencing and strip hybridization assay were used. All patients were also analyzed for KRAS and EGFR mutations. Results BRAF mutations were present in 36 ADCs (4.9%) and one SCC (0.3%; P = .001). Twenty-one of the mutations (56.8%) were V600E, and 16 (43.2%) were non-V600E. V600E mutations were significantly more prevalent in females (16 of 187 patients; 8.6%) than in males (five of 552 patients; 0.9%), as indicated by multivariate logistic regression analysis (hazard ratio [HR], 11.29; P < .001). V600E-mutated tumors showed an aggressive histotype characterized by micropapillary features in 80% of patients and were significantly associated with shorter disease-free and overall survival rates on both univariate (HR, 2.67; P < .001 and HR, 2.97; P < .001, respectively) and multivariate analyses (HR, 2.19; P = .011 and HR, 2.18; P = .014, respectively). All non-V600E mutations were found in smokers (P = .015) and were associated with neither clinicopathologic parameters nor prognosis. BRAF and EGFR were concomitantly mutated in two tumors. Conclusion We report for the first time to our knowledge that V600E and non-V600E BRAF mutations affect different patients with NSCLC. V600E mutations are significantly associated with female sex and represent a negative prognostic factor. In addition, we identified a number of other clinicopathologic parameters potentially useful for the selection of patients carrying BRAF mutations.