BRAFV600Emutation has been investigated by immunohistochemistry and has shown high sensitivity and specificity. We aim to investigate the accuracy of immunohistochemistry versus molecular testing of BRAFV600Ein papillary thyroid cancer using a large number of polymerase chain reaction–positive BRAFV600Epapillary thyroid cancer tissues.Methods.
We stained 130 formalin-fixed papillary thyroid cancer specimens using the VE1 antibody: 100 BRAFV600Epositive and 30 BRAFV600Enegative confirmed by PCR. The sensitivity, specificity, and predictive values of the antibody were assessed.Results.
Immunohistochemistry of BRAFV600Eshowed 98.0% sensitivity, 93.3% specificity, and positive and negative predictive values of 98.0% and 93.3%, respectively. Of 100 patients with BRAFV600EPCR-positive samples, 97 (97.0%) had cytoplasmic weak (4.0%), moderate (17.0%), and strong (76.0%) immunostaining. In BRAFV600EPCR-negative samples, cytoplasmic staining was not detected in 93.3% (28/30) of papillary thyroid cancer tissues. The receiver operating characteristic curve demonstrated a high validity and comparable immunohistochemistry method (area under the curve = 98.8%) compared with PCR testing.Conclusion.
The use of VE1 immunohistochemistry for the detection of BRAFV600Ein papillary thyroid cancer tissues is a clinically applicable method with high specificity, sensitivity, and positive and negative predictive values. The reliable use of BRAFV600Eimmunohistochemistry should promulgate the routine use of this method for BRAFV600Edetection in papillary thyroid cancer tissues.