Analysis of the BRAF(V600E) Mutation in Thyroid Nodules: the Preoperative Diagnostic Role of Fine-needle Aspiration Biopsy for Patients with Papillary Thyroid Cancer and Its Impact on Patient Care

ABSTRACT

PURPOSE: We wanted to evaluate the frequency of BRAF(V600E) mutations on the preoperative fine-needle aspiration biopsies (FNAB) of thyroid nodules and the effect of this on the accuracy of diagnosing papillary thyroid cancer (PTC). We also wanted to evaluate the influence of BRAF(V600E) analysis on patient care. MATERIALS AND METHODS: The results of cytology and BRAF(V600E) mutation analysis of 190 thyroid nodules were retrospectively reviewed. The results of the cytology and BRAF(V600E) analysis were compared with the histopathological diagnosis for the surgically confirmed cases, and we calculated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and the diagnostic accuracy of FNAB and combining the modalities of FNAB and BRAF(V600E) mutation. The frequency of BRAF(V600E) mutation according to age and the influence of BRAF(V600E) analysis on patient care were studied. The nodule size was compared between the malignant and other categories of BRAF(V600E) positive nodules. RESULTS: Seventy four percent of the PTC were BRAF(V600E) positive. BRAF(V600E) analysis increased the sensitivity, NPP and diagnostic accuracy of FNAB. Fifty percent of the BRAF(V600E) positive nodules with other than malignant cytology received surgery and these were confirmed to be PTC. The frequency of BRAF(V600E) mutation increased with age, which was statistically significant. There was a statistically significant difference in the nodule size between the cytologically malignant nodules and the other nodules. CONCLUSION: BRAF(V600E) analysis increased the diagnostic accuracy of FNAB and it should be considered as being complementary to cytological analysis. The frequency of the BRAF(V600E) mutation increased with age. The size of the malignant nodules was larger than that of the benign nodules.