Detection of Plasma BRAF(V600E) Mutation Is Associated with Lung Metastasis in Papillary Thyroid Carcinomas

PURPOSE: The BRAF(V600E) mutation represents a novel indicator of the progression and aggressiveness of papillary thyroid carcinoma (PTC). The purpose of this study was to determine the clinical significance of free circulating mutant BRAF(V600E) in predicting the advanced disease of PTC. MATERIALS AND METHODS: Seventy seven matched tumor and plasma samples obtained from patients with both benign and PTC were analyzed for BRAF(V600E) mutation using a peptide nucleic acid (PNA) clamp real-time polymerase chain reaction (PCR). RESULTS: The BRAF(V600E) mutation was absent in tumor DNA samples obtained from patients with benign follicular adenomas or adenomatous goiter. In contrast, 49 of 72 (68.1%) PTC tumors were positive for the BRAF(V600E) mutation. Among them, 3 (6.1%) patients with PTC were positive for BRAF(V600E) mutation in plasma and tumor. However, all 3 patients (100%) had lateral lymph node and lung metastasis. CONCLUSION: These findings suggest that the BRAF(V600E) mutation can be detected using a PNA clamp real-time PCR in the blood of PTC patients with lung metastasis. Future studies are warranted to determine clinical significance of serum BRAF(V600E) mutation in large prospective studies.