VE1 immunohistochemistry is an adjunct tool for detection of BRAFV600E mutation: Validation in thyroid cancer patients

Abstract

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy among other endocrine tumors, and BRAFV600E 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 BRAFV600E mutation. Therefore, the study aimed to evaluate diagnostic accuracy of VE1 IHC for detecting the BRAFV600E mutation frequency and clinical implementation in diagnostic laboratories. In this study, 72 formalin fixed paraffin-embedded tissues (FFPE) were used to determine the BRAFV600E 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 BRAFV600E 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, BRAFV600E detection through IHC has been considered as the best tailored technique for routine pathology laboratories.