Initial clinical experience with BRAF(V600E) mutation analysis of core-needle biopsy specimens from thyroid nodules

Abstract

OBJECTIVE: The accurate diagnosis of thyroid nodules is important for making management decisions. The purpose of this study was to evaluate the feasibility of core-needle biopsy with BRAF(V600E) mutation analysis (CNB + BRAF(V600E) ) and to compare the clinical usefulness of CNB + BRAF(V600E) and fine-needle aspiration with BRAF(V600E) mutation analysis (FNA + BRAF(V600E) ) in the diagnosis of thyroid malignancy. DESIGN, PATIENTS AND MEASUREMENTS: The results of BRAF(V600E) mutation analyses of 820 nodules from 820 patients (153 men, 667 women: mean age, 51.1 years), who underwent CNB + BRAF(V600E) (n = 256) or FNA + BRAF(V600E) (n = 564) between January 2011 and March 2012 were retrospectively evaluated. The feasibility of CNB + BRAF(V600E) was assessed by comparing its rate of detection of BRAF(V600E) mutations and positive predictive value with those of FNA + BRAF(V600E) . The clinical usefulness of CNB + BRAF(V600E) was determined by comparing rates of inconclusive results, the additional value of BRAF(V600E) mutation analysis, diagnostic surgery and diagnostic performance with those of FNA + BRAF(V600E) . RESULTS: CNB + BRAF(V600E) and FNA + BRAF(V600E) had similar rates of BRAF(V600E) mutation detection (66.3% vs 64.4%, P = 0.883) and positive predictive value (100.0% vs 96.6%, P = 0.135). CNB + BRAF(V600E) had a significantly higher diagnostic accuracy rate (95.7% vs 85.9%, P < 0.001), and significantly lower rates of inconclusive results (8.2% vs 51.8%, P < 0.001), and diagnostic surgery (8.9% vs 22.3%, P = 0.006), than FNA + BRAF(V600E) . CONCLUSIONS: The greater diagnostic performance of CNB + BRAF(V600E) and its lower rate of inconclusive results than FNA + BRAF(V600E) suggest that CNB + BRAF(V600E) can reduce rates of preventable diagnostic surgery.