Detectable BRAF mutation in serum DNA samples from patients with papillary thyroid carcinomas.

BACKGROUND.: An activating point mutation of the BRAF oncogene results in a V600E amino acid missense mutation found in a majority of papillary thyroid carcinomas (PTC). METHODS.: In this study, 28 matched tumor and serum samples obtained from patients with both benign and malignant thyroid disorders were analyzed for BRAF mutation using a gap-ligase chain reaction technique. RESULTS.: The BRAF mutation was absent in tumor DNA samples obtained from patients with benign adenomas, follicular neoplasms or carcinoma, and thyroid lymphoma. In contrast, 5 of 14 PTC tumors were positive for the BRAF mutation. Moreover, 3 of 14 patients with PTC were positive for BRAF mutation in serum and tumor. Of these 3 patients, 2 had lymph node metastasis and 2 had PTC in background of the Hashimoto's thyroiditis. CONCLUSIONS.: The detection of free circulating mutant BRAF in patients with PTC is possible and future studies are warranted to determine its clinical significance.