Association between BRAFV600E mutation and the clinicopathological features in incidental papillary thyroid microcarcinoma: a single-center study in Turkish patients

Abstract

Objective: In this study, we evaluated the influences of BRAF(V600E) mutation on clinicopathological features in incidentally found papillary thyroid microcarcinomas (PTMCs). Methods: This retrospective cohort study included 72 patients with PTMC who underwent surgery from 2008 to 2012. The mean follow-up of the whole cohort was three years. DNA was isolated using QIAamp DNA formalin-fixed, paraffin-embedded (FFPE) tissue kit. BRAF gene was amplified by the polymerase chain reaction-restriction fragment length (PCR-RFL) polymorphism method with the following primers. The clinicopathologic features (age, gender, histologic subtype, tumor size, presence of tumor capsule, bilaterality, multifocality, extrathyroidal extension (ETE), thyroid capsular invasion, presence of Hashimoto's thyroiditis, lymph node metastasis (LNM) and distant metastasis) were compared between the BRAF (+) and BRAF (-) patient groups. Results: BRAF(V600E) mutation was detected in 30 of the 72 patients (41.6%). The presence of the mutation was statically significantly associated with classic variant (p=0.046), invasion of thyroid capsule (p=0.002) and absence of tumor capsule (p=0.003). Conclusion: Although incidental PTMCs positive for the BRAF(V600E) mutation had more invasive behavior, the presence of the mutation was not associated with recurrences within three years of follow-up.