Purpose BRAF mutations are found in a subset of non-small cell lung cancers (NSCLCs). We examined the clinical characteristics and treatment outcomes of patients with NSCLC harboring BRAF mutations. Experimental Design Using DNA sequencing, we successfully screened 883 NSCLC patients for BRAF mutations between 7/1/09 and 7/16/12. Baseline characteristics and treatment outcomes were compared between patients with and without BRAF mutations. Wild type controls consisted of NSCLC patients without a somatic alteration in BRAF, KRAS, EGFR, and ALK. In vitro studies assessed the biological properties of selected non-V600E BRAF mutations identified from NSCLC patients. Results Of 883 tumors screened, 36 (4%) harbored BRAF mutations (V600E: 18; non-V600E: 18) and 257 were wild type for BRAF, EGFR, KRAS, and ALK negative. Twenty-nine of the 36 BRAF mutant patients were smokers. There were no distinguishing clinical features between BRAF mutant and wild type patients. Advanced NSCLC patients with BRAF mutations and wild type tumors showed similar response rates and progression-free survival (PFS) to platinum-based combination chemotherapy and no difference in overall survival. Within the BRAF cohort, patients with V600E mutated tumors had a shorter PFS to platinum-based chemotherapy compared to those with non-V600E mutations, although this did not reach statistical significance (4.1 versus 8.9 months; P=0.297). We identified five BRAF mutations not previously reported in NSCLC; two of the five were associated with increased BRAF kinase activity. Conclusions BRAF mutations occur in 4% of NSCLCs and half are non-V600E. Prospective trials are ongoing to validate BRAF as a therapeutic target in NSCLC.

Introduction Activating mutations in the epidermal growth factor receptor (EGFR) predict for prolonged progression-free survival in patients with advanced non-small cell lung cancer (NSCLC) treated with EGFR-tyrosine kinase inhibitors (EGFR-TKIs) versus chemotherapy. Long-term survival outcomes, however, remain undefined. The objective of this study was to determine the 5-year survival in these patients, and identify clinical factors associated with overall survival (OS). Methods Patients with EGFR-mutant metastatic lung adenocarcinoma treated with erlotinib or gefitinib at Dana-Farber Cancer Institute between 2002 and 2009 were included. OS was analyzed. Results Among 137 patients, median PFS and OS were 12.1 months (95% CI, 10.2-13.5 months) and 30.9 months (95% CI, 28.2-35.7 months), respectively. Twenty patients (14.6%) were 5-year survivors. In multivariate analysis, exon 19 deletions (hazard ratio [HR], 0.63; 95% CI, 0.44-0.91; P = 0.01), absence of extrathoracic (HR 0.62; 95% CI, 0.41-0.93; P = 0.02) or brain metastasis (HR 0.48; 95% CI, 0.30-0.77, P = 0.002), and not a current smoker (HR 0.23; 95% CI, 0.09-0.59; P = 0.002) were associated with prolonged OS. Age, gender, stage at diagnosis, liver or bone or adrenal metastasis, specific TKI, and line of TKI therapy were not associated with OS. Conclusions Our data suggest that the prevalence of 5-year survival among EGFR-mutant metastatic lung adenocarcinoma patients treated with erlotinib or gefitinib is 14.6%. Exon 19 deletions and absence of extrathoracic or brain metastasis are associated with prolonged survival. Based on our findings, clinicians can gain an enhanced estimation of long-term outcomes in this population.