VE1 immunohistochemistry is an adjunct tool for detection of BRAF mutation: Validation in thyroid cancer patients.

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy among other endocrine tumors, and BRAF is a frequent genetic mutation occurring in the disease. Although different molecular techniques, most importantly sequencing has been widely recognized as a gold standard but molecular diagnosis remains an expensive, laborious, and time-intensive process. Recently, immunohistochemistry (IHC) with anti-BRAF V600E (VE1) antibody has increased practical utility and implemented clinically for the detection of BRAF mutation. Therefore, the study aimed to evaluate diagnostic accuracy of VE1 IHC for detecting the BRAF mutation frequency and clinical implementation in diagnostic laboratories. In this study, 72 formalin fixed paraffin-embedded tissues (FFPE) were used to determine the BRAF mutation status using IHC and Sanger sequencing. The mutation was found in 29% and 28% cases using IHC and Sanger sequencing, respectively. Furthermore, the results showed 100% sensitivity, 98.07% specificity, 95.2% positive predictive value, and 100% negative predictive value. Notably, significant associations were found between BRAF status and tumor stage, tumor focality, and extrathyroidal extensions, respectively. VE1 IHC was found to be a highly sensitive, specific, and diagnostically accurate method in this cohort. Therefore, BRAF detection through IHC has been considered as the best tailored technique for routine pathology laboratories.