Comparison of Immunohistochemistry and DNA Sequencing for BRAF V600E Mutation Detection in Mandibular Ameloblastomas

Author(s)

da Silva Marcelino, Barbara M. R. ; Parise, Guilherme K. ; do Canto, Alan M. ; Sassi, Laurindo M. ; Sarmento, Dmitry J. S. ; Costa, Andre L. F. ; Hasseus, Bengt ; Kjeller, Goran ; Schussel, Juliana L. ; Braz-Silva, Paulo H.

• Document type: Journal article
• Source: APPLIED IMMUNOHISTOCHEMISTRY & MOLECULAR MORPHOLOGY; v. 29, n. 5, p. 4-pg., 2021-05-01.

Abstract

This study aimed to investigate the presence of BRAF V600E mutation in mandibular ameloblastoma by comparing the results of molecular detection and immunohistochemical analysis. A 128 cases of mandibular ameloblastoma and 30 cases of dentigerous cyst (control group) were selected for analysis. Detection of BRAF V600E mutation was performed with immunohistochemistry (IHC) and polymerase chain reaction techniques. Clinico-pathologic data were collected in order to investigate possible associations with the mutation. Of the 128 cases submitted to IHC, 81.2% (108 cases) showed positivity for anti-BRAF V600E antibody, whereas 24 were negative (18.8%). Molecular analysis of the BRAF V600E mutation by polymerase chain reaction was possible in 116 cases due to DNA quality. Of these cases, 96 were positive (82.8%) and 20 negative (17.2%). All cases of dentigerous cyst were negative for BRAF V600E mutation in both techniques. Considering the sequencing as a gold standard method, the receiver operating characteristics curve analysis showed sensitivity of 0.99 and specificity of 1 (area under the curve=0.995, standard error=0.006; P<0.001; 95% confidence interval=0.983 to 1). We also tested the agreement between the techniques by using the Cohen's kappa coefficient, with kappa being 0.97 (P<0.001). IHC is a reliable test for identifying the BRAF V600E mutation in ameloblastomas, presenting advantages such as being more frequently used in surgical pathology laboratories and requiring fewer critical steps for paraffin-embedded tissue compared with molecular biology techniques. (AU)

• FAPESP's process: 17/18576-7 - Immunohistochemical analysis of cytokeratins, CD10, podoplanin and BerEp4 in ameloblastomas
• Grantee: Bárbara Michaela Reis da Silva Marcelino
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 15/07727-9 - Evaluation of immunoregulatory microenvironment of oral premalignant lesions, squamous cell carcinomas and oropharyngeal carcinomas related to HPV or not.
• Grantee: Paulo Henrique Braz da Silva
• Support Opportunities: Regular Research Grants