Prognostic Assessment of BRAF Mutation in Preoperative Thyroid Fine-Needle Aspiration Specimens

Abstract

Objectives: We investigate the potential role of BRAF testing in guiding surgical intervention in papillary thyroid carcinoma (PTC).

Methods: Thyroid fine-needle aspiration (FNA) cases with available BRAF result and follow-up thyroidectomy for PTC were included in the study. Cytology and surgical diagnoses were correlated with BRAF status.

Results: There were 151 cases of thyroid FNA specimens with BRAF testing (70 mutant and 81 wild-type BRAF) and histologically confirmed unilateral, unifocal PTCs. There were no differences in age, sex, tumor size, or lymphovascular invasion on thyroidectomy specimens between mutant and wild-type BRAF cases. BRAF mutation was significantly associated with cytology diagnosis (P < .001), PTC subtype (P < .001), extrathyroidal extension (ETE) (P = .006), and higher tumor (T) stage (P = .04). However, an analysis within the histologic subtypes of PTC revealed no significant association between BRAF mutation and ETE or higher T stage. There was also no difference in central (P = .847) or lateral (p = 1) neck lymph node (LN) metastasis.

Conclusions: BRAF mutation identified in thyroid FNA specimens correlates with histologic subtypes but is not an independent factor for predicting PTC biological behavior and should not be used to guide the extent of LN dissection.

Keywords: BRAF; Fine-needle aspiration; Lymph node metastasis; Papillary thyroid carcinoma (PTC); Prognostic factors.