ASSOCIATION OF BRAF V600E MUTATION WITH POOR CLINICOPATHOLOGICAL OUTCOMES IN 500 CONSECUTIVE CASES OF PAPILLARY THYROID CARCINOMA.

In this study, BRAF mutation was found in 219 of 500 cases (43.8%). In particular, we found the most common BRAF V600E mutation in 214 cases (42.8%), BRAF K601E mutation in three cases (0.6%), BRAF VK600–1E (0.2%) in one case, whereas in one case we found a new 14-bp deletion with concomitant 2-bp insertion, VKSR600–3del and T599I, respectively. BRAF V600E was associated with extrathyroidal invasion (P 0.0001), multicentricity (P 0.0026), presence of nodal metastases (P 0.0009), class III vs. classes I and II (P 0.00000006), and absence of tumor capsule (P 0.0001), in particular in follicular- and micro-PTC variants. By multivariate analysis, the absence of tumor capsule remained the only parameter associated (P 0.0005) with BRAF V600E mutation.