Value of the detection of BRAF(V600E) gene mutation and protein expression in auxiliary cytological diagnosis of papillary thyroid carcinoma

Abstract

Objective: To evaluate the utility of the BRAF(V600E) mutation detection in different cytoloy categories and to determine if the VE1 antibody can serve as a screening tool for the detection of BRAF(V)600E mutation in thyroid fine needle aspiration (FNA) specimens. Methods: A total of 273 FNA residual specimens were collected. BRAF(V600E) testing was performed on these liquid-based specimens. And also 78 specimens with enough residual cells were stained with VE1 antibody. Comparisons of molecular and immunocytochemistry results with clinicopathological outcomes were performed. SPSS 17.0 software was used to analyze the data. Results: There were 70 indeterminated diagnoses in 273 cases with FNAs. Fifty-eight cases were proven to be papillary thyroid carcinoma (PTC) by histology, including 9 cases of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), 3 cases of follicular neoplasm/suspicious for follicular neoplasm (FN/SFN), and 46 cases of suspicious for malignancy (SM). BRAF(V600E) analysis detected PTC in 3 of 9 cases with AUS/FLUS, and in 31 (67.4%) of 46 cases with SM. The sensitivity of immunostaining with VE1 antibody was 62.8%(27/43) and the specificity was 91.4% (32/35). VE1 expression showed moderately concordance with the molecular mutation (κ=0.524, P<0.001). Conclusions: Additional BRAF(V600E) detecting can improve the diagnostic efficacy for PTC in AUS/FLUS and SM. VE1 expression may be an alternative method for BRAF(V600E) detecting when molecular detecting is unavailable.