BRAFV600E mutation is correlated with the biological behaviors of papillary thyroid microcarcinoma: a Meta-analysis

Objective To evaluate the association between V-raf murine sarcoma viral oncogene homolog B1 (BRAF)V600E mutation and biological behaviors of papillary thyroid (PTMC). Methods Published papers about the association between BRAFV600E mutation and aggressiveness of from January 2011 to January 2016 were collected using databases of Wanfang, VIP, China National Knowledge Infrastructure (CNKI), PubMed, Embase and Cochrane library. The key words were PTMC , papillary thyroid microcarcinoma , thyroid microcarcinoma , micropapillary thyroid carcinoma , BRAF . The languages were restricted to English and Chinese. Meta-analysis was performed with RevMan 5.3 software. Results Eighteen studies involving 2 938 patients were included. A total of 1 536 patients showed BRAFV600E mutation-positive results, and 1 402 patients were with wild type. The average prevalence of the BRAFV600E mutation was 52.3%. The BRAFV600E mutation was associated with the multifocality (odds ratio (OR)=1.37, 95% CI: 1.11-1.67), extrathyroid extension(OR=2.25, 95% CI: 1.31-3.86), lymph node metastases(OR=3.05, 95% CI: 1.60-5.79), advanced stage (TNM Ⅲ+ Ⅳ; OR=1.99, 95% CI: 1.54-2.57), recurrence(OR=2.92, 95% CI: 1.84-4.65), male patients(OR=1.70, 95% CI: 1.35-2.14) and tumor diameter >5 mm(OR=1.62, 95% CI: 1.29~2.04)of PTMC. There was no significant association between BRAFV600E mutation and age or distant metastases. Conclusion BRAFV600E mutation is a risk factor for aggressive behaviors of PTMC. Key words: Thyroid neoplasms; Proto-oncogene proteins B-raf; Mutation; Meta analysis