Avaliação da mutação BRAF V600E em ameloblastomas

Abstract

Ameloblastoma is a benign odontogenic tumor that, due to its frequency and behavior, has high clinical relevance. Of epithelial origin, it resembles, histologically, the enamel organ, being characterized by its slow growth, aggressive behavior with high infiltrative power and, consequently, high recurrence capacity. Its treatment is performed through surgical resection, which will cause face deformity and high risk of morbidity to the patient. To reduce the impact of this invasive treatment, researchers have been constantly investigating solid and unicystic ameloblastomas pathogenesis. The BRAF V600E mutation was found in high frequencies in the samples, which is also present in melanoma, thyroid and colorectal cancers carcinogenis. The presence of the mutation can be accessed through sensitive research techniques, such as allele specific PCR, or Sanger sequencing, as well as through mutated BRAF oncoprotein identification, with the use of immunohistochemistry (IHC). IHQ is a simpler, economical and already used technique for evaluation of the mutation as well as the correlation of the BRAF V600E status with clinical features of ameloblastomas. In this context, in view of BRAF V600E mutation clinical implication in the treatment or behavior of ameloblastoma and absence of data on this mutation in tumors of the University Hospital of the Federal University of Sergipe (HU / UFS), this study intends to investigate the BRAF V600E mutation frequency in the HU / UFS ameloblastomas. A paraffin block search and clinical data from HU / UFS Pathology Laboratory samples and bone tumors were used for histological examinations for IHQ analysis with the anti-BRAFV600E antibody. Of the 8 ameloblastoma samples found, 62.5% were positive for the BRAF V600E mutation. In addition, the average age was 27 years, with a predilection for females and predominance in the posterior region of the mandible (60%). The high frequency of mutations is found in the literature and points to the possibility of using a follow-up therapy in cases of ameloblastoma.