Detection and evaluation of the presence of the BRAF V600E mutation in ameloblastomas in an Indian population

Abstract

Introduction: Ameloblastoma is a benign epithelial odontogenic neoplasm that constitutes approximately 1% of all oral tumors and about 9 to 11% of all odontogenic tumors. They are slow-growing, locally invasive, and demonstrate a potential for metastasis and malignant transformation. The molecular pathogenesis of ameloblastoma is attributed to aberrant activity of the signal transduction pathways relating to developmental stages of odontogenesis including the mitogen-activated protein kinase (MAPK) pathway. The BRAF V600E mutation was identified as the most frequently mutated gene in this neoplasm. Studies have shown that use of BRAF inhibitors in patients diagnosed with ameloblastomas led to a significant reduction in tumor volume.

Aims: To detect the expression of BRAF V600E mutation in ameloblastomas in an Indian population using immunohistochemistry. To compare the difference in the occurrence of the BRAF V600E mutation between mandibular and maxillary cases.

Materials and methods: Thirty-three formalin-fixed paraffin-embedded tissues of histopathologically proven cases of ameloblastoma were assessed for the BRAF V600E mutation by immunohistochemistry using the BRAF V600E monoclonal antibody. Patient data such as age, sex, anatomical site, recurrence were documented.

Statistical analysis: The statistical analysis was performed using the Pearson Chi-square test and Student's t-test.

Results: The present study revealed a high expression of the BRAFV600E mutation in mandibular cases of ameloblastoma among Indians irrespective of the age, sex, site, recurrence or histological pattern.

Conclusions: The identification of this driver mutation opens the possibility of an adjuvant therapeutic modality to reduce the significant facial disfigurement and morbidity following surgical management.

Keywords: Ameloblastoma; BRAF V600E mutation; immunohistochemistry.