RESUMO
Introduction: Growing evidence has shown that cyclooxygenase-2 (COX-2), an enzyme capable of catalyzing prostaglandin production, plays a key role in carcinogenesis. Selective COX-2 inhibitors have been shown to reduce the establishment of tumors such as oral squamous cell carcinoma (OSCC) and premalignant conditions such oral submucous fibrosis (OSMF) in experimental models. The aim of this study was to investigate the immunohistochemical expression of COX-2 in OSCC and OSMF with the normal oral mucosa as control. Material and Methods: Forty-five formalin-fixed paraffin-embedded samples comprising 20 OSCC, 20 OSMF, and 5 normal oral mucosa specimens were withdrawn from the archives of the Department of Oral and Maxillofacial Pathology for immunohistochemical examination for COX-2 expression. Negative and less than 5% COX-2 positivity was considered negative expressions, while greater than or equal to 5% COX-2 positivity was considered positive expression. The data obtained were statistically analyzed. Results: The difference in percentages of expression in normal mucosa, OSCC, and OSMF was highly significant (P < 0.01). In comparison to normal mucosa, OSCC and OSMF had an increased level of COX-2 expression. However, there was an insignificant difference between the various histological gradings of OSCC and OSMF. Conclusion: The results of the present study confirm the role of COX-2 in carcinogenesis and in the progression of premalignant conditions to malignancy.
RESUMO
Ameloblastoma is a benign, locally aggressive neoplasm that needs extensive surgical resection. The goal of this article is to obtain an in-depth review of benign ameloblastomas to determine the available level of evidence and the possible benefit of targeted therapeutics for the treatment of ameloblastoma and BRAF V600E mutation in ameloblastoma. An electronic literature search was conducted according to PRISMA guidelines in PubMed/MEDLINE, EBSCO, and Web of Science for eligible studies published between 1975 and 2021. The systematic review is registered with INPLASY (INPLASY202260018). The review included 2 case series and 17 case reports. The histopathological type, anatomic location, expression of BRAF mutation, additional mutations, and molecular-targeted therapies of the 19 reviewed articles were summarized and tabulated. Interestingly, the majority of the primary site of ameloblastoma was located in the mandible (80.9%) compared to the maxilla (17%). The tumour size was reported in nine of the included studies. Most of the included studies in the review exhibited ameloblastoma with BRAF V600E mutations and responded to molecular-targeted therapies. Molecular therapies employing BRAF and/or MEK inhibitors in ameloblastoma with BRAF V600E mutations proved to be an appropriate treatment based on the limited available evidence. It is essential further to deepen our understanding at the clinical and molecular level to enhance the precision of management of ameloblastoma.