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.