Prevalence and Clinicopathological Characteristics of BRAF Mutations in Chinese Patients with Lung Adenocarcinoma.

BACKGROUND: This study was designed to identify the prevalence of BRAF mutations in Chinese patients with lung adenocarcinoma, and to reveal the association between BRAF mutations and clinicopathological characteristics in these patients. METHODS: From October 2007 to February 2013, patients with newly diagnosed primary lung adenocarcinoma were detected for mutations in BRAF, EGFR, KRAS, HER2 and ALK. Clinicopathological characteristics, including sex, age, TNM stage, tumor differentiation, smoking status, histological subtypes, and survival information were analyzed. RESULTS: Of 1358 patients with lung adenocarcinoma, 20 patients were harboring BRAF mutations, including five BRAF V600E mutations and 15 BRAF non-V600E mutations. Among these, BRAF N581I and BRAF G593S were newly reported. BRAF mutations were associated with smoking status (odds ratio 3.28; 95 % CI 1.33-8.08; p = 0.008). In patients less than 60 years of age, BRAF mutations tended to have poor differentiation in tumor samples (70.0 vs. 35.1 %; p = 0.014), and were more likely to relapse (70 vs. 28 %; p = 0.008). A significant difference was found in relapse-free survival (RFS) between BRAF mutations and other mutations, but not in overall survival. CONCLUSIONS: The prevalence of BRAF mutations in Chinese patients with lung adenocarcinoma was approximately 1.5 %. BRAF mutations were more frequent in current smokers. Patients harboring BRAF mutations had a higher rate of recurrence and worse RFS compared with other patients.