<i>BRAF</i> Mutation Analysis of Fine-Needle Aspiration Biopsies of Papillary Thyroid Carcinoma: Impact on Diagnosis and Prognosis

Abstract

OBJECTIVE: The BRAF V600E mutation has been associated with aggressive disease in papillary thyroid carcinoma (PTC). Molecular testing has been proposed as a useful adjunct to cytology in the diagnosis of malignancy and for tailoring clinical management. The aims of our study were to evaluate the BRAF mutational status using archived fine-needle aspiration biopsy (FNAB) material from patients with long-term follow-up and to correlate it with the original cytology diagnosis, clinicopathological stage at surgery, and prognosis. STUDY DESIGN: FNAB material from 52 cases of PTC, with a mean follow-up of 8.4 years, was used in this study. DNA was extracted from archival cytology slides. Mutation analysis was performed by standard sequencing and locked nucleic acid-PCR/sequencing. RESULTS: The BRAF V600E mutation was present in 46% of cases, but it was absent in all FNABs diagnosed originally as atypical and in 14 of 17 suspicious cases. Recurrence was significantly more frequent (p = 0.006) in cases with BRAF mutations and 54% of these cases presented with stage 2 or higher. CONCLUSION: The BRAF V600E mutation is associated with a higher pathological stage at surgery and a higher rate of recurrence. BRAF mutation analysis did not provide a significant increase in the accuracy of thyroid FNABs diagnosed as suspicious or atypical in our institution.