Role of BRAF V600E mutation as an indicator of the extent of thyroidectomy and lymph node dissection in conventional papillary thyroid carcinoma

Abstract

The extent of surgery for papillary thyroid carcinoma (PTC) is associated strongly with disease persistence, recurrence, and mortality. It is difficult, however, to determine the optimal extent for surgery. The BRAF mutation is well known for its diagnostic and prognostic value in PTC. Among the variants of PTC, the clinical importance of the BRAF mutation has been associated particularly with conventional PTC. The goal of this study was to clarify the role of the BRAF mutation as a determinant for the operative extent in conventional PTC. Histopathology and BRAF mutation status of 3,019 patients with conventional PTC were analyzed. With regard to the extent of surgery in PTC, focus was given to the factors of tumor bilaterality, central lymph node metastasis (CLNM), and lateral lymph node metastasis. In addition, the prognostic impact of BRAF mutation on loco-regional recurrence was investigated. The BRAF mutation was found to be an independent indicator of tumor bilaterality (odds ratio [OR] 1.484, P = .010); however, it was not an independent indicator of CLNM (OR 1.167, P = .254) or lateral lymph node metastasis (OR 0.647, P = .384). Moreover, it was not an independent indicator of CLNM in either the therapeutic or prophylactic central neck dissection. Finally, BRAF mutation positivity did not increase the risk of loco-regional recurrence (adjusted hazard ratio = 0.829, P = .523). The BRAF mutation is a possible indicator for determining the extent of thyroidectomy required but not for the extent of lymph node dissection and prognosis in patients with conventional PTC.