Prognostic Prediction of BRAFV600E and its Relationship with Sodium Iodide Symporter in Classic Variant of Papillary Thyroid Carcinomas

Background: The aim of this study was to evaluate the prognosis of the classic variant of papillary thyroid carcinomas with the BRAF(V600E) mutation and I-131 treatment failure in those tumors due to lower functional sodium iodide symporter expression. Methods: 109 papillary thyroid carcinomas were associated with clinicopathologic features. The BRAF(V600E) mutation was evaluated by direct sequencing and sodium iodide symporter protein was determined by immunohistochemistry. Results: We found that the BRAF(V600E) mutation was significantly associated with the classic variant of papillary thyroid carcinomas and was independent of tumor size, the presence of extrathyroid invasion and lymph node metastasis, advanced TMN stages, and a high risk of disease recurrence. Moreover, the BRAF(V600E) mutation was associated with a statistically significant lower functional NIS protein expression in the classic variant of papillary thyroid carcinomas. However, those statistically significant relationships were not found in the follicular variant of papillary thyroid carcinomas. Conclusions: The BRAF(V600E) mutation might be associated with a more aggressive phenotype and a poor prognosis, causing less NIS-mediated I-131 uptake due to a lower functional NIS protein expression in the classic variant of papillary thyroid carcinomas. Our current study appears to be valuable for predicting prognosis and is of important clinical significance for surgery and 1311 treatment in patients with the classic variant of papillary thyroid carcinomas. (Clin. Lab. 2012;58:919-926. DOT: 10.7754/Clin.Lab.2012.111217)