Is the BRAF ^V600E mutation useful as a predictor of preoperative risk in papillary thyroid cancer?

Objective: Recent studies have shown that a BRAF ^V600E reflects poor prognosis, mainly in Western countries. However, some clinicians in Japan have suggested that the BRAF ^V600E mutation is not associated with a poor prognosis. Therefore, we investigated a relationship between BRAF ^V600E mutation and clinicopathologic factors. Methods: From September 2008 to December 2009, we performed routine analysis of the BRAF ^V600E mutation using thyroid cancer tissue from 424 patients who underwent thyroidectomy with cervical lymph node dissection. Results: The BRAF ^V600E mutation was found in 335 of 424 cases (79%) and was higher in classic papillary thyroid carcinoma (PTC) (79.7%) than in the follicular variant of PTC (62.5%) (P =.019). On univariate analysis, the BRAF ^V600E mutation was associated with extrathyroidal extension (P =.009) and variants of PTC (P =.019), but a high-risk Metastasis, Patient Age, Completeness of resection, local Invasion and Tumor Size (MACIS) score (≥ 6) (P =.146) and lymph node metastasis (P =.628) were not significantly associated with the BRAF ^V600E mutation. Multivariate analysis showed that extrathyroidal extension is independently associated with the BRAF ^V600E mutation (relative ratio: 2.466; 95% confidence interval, 1.2135.011; P <.013). Conclusion: It is not clear that the BRAF ^V600E mutation is useful for prediction of poor prognosis of PTC.