Analysis of BRAF super(V600E) mutation and DNA methylation improves the diagnostics of thyroid fine needle aspiration biopsies

• Published in: Diagnostic pathology 2014-01, Vol.9 (1), p.45-45
• Main Authors: Zhang, Bingfei, Liu, Shu, Zhang, Zhaoxia, Wei, Jing, Qu, Yiping, Wu, Kexia, Yang, Qi, Hou, Peng, Shi, Bingyin
• Format: Article
• Language: English
• ISSN: 1746-1596; 1746-1596
• DOI: 10.1186/1746-1596-9-45

Background: Thyroid nodules with indeterminate cytological features on fine needle aspiration biopsy specimens (FNABs) have a ~20% risk of thyroid cancer. BRAF super( V600E ) mutation and DNA methylation are useful markers to distinguish malignant thyroid neoplasm from benign. The aim of this study was to determine whether combined detection of BRAF super( V600E ) mutation and methylation markers on FNABs could improve the diagnostic accuracy of thyroid cancer. Methods: Using pyrosequencing and quantitative methylation-specific PCR (Q-MSP) methods, FNABs from 79 and 38 patients with thyroid nodules in training and test groups, respectively, were analyzed for BRAF super( V600E ) mutation and gene methylation. Results: BRAF super( V600E ) mutation was found in 30/42 (71.4%) and 14/20 (70%) FNABs in training and test groups, respectively. All BRAF super( V600E )-positive samples were histologically diagnosed as papillary thyroid cancer (PTC) after thyroidectomy. As expected, BRAF mutation was not found in all benign nodules. Moreover, we demonstrated that the five genes, including CALCA, DAPK1, TIMP3, RAR-beta and RASSF1A, were aberrantly methylated in FNABs. Of them, methylation level of DAPK1 in PTCs was significantly higher than that in benign samples (P