Avaliação de parâmetros para identificação do potencial de transformação contido em lesões orais potencialmente malignas

• Ano de defesa: 2012
• Autor(a) principal: Silva, Deise de Avila
• Orientador(a): Gomes, Ana Paula Neutzling
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Pelotas
• Programa de Pós-Graduação: Programa de Pós-Graduação em Odontologia
• Departamento: Odontologia
• País: BR
• Palavras-chave em Português: Carcinoma espinocelular; Leucoplasia; Displasia epitelial oral; MAGE (Y-18); Imuno-histoquímica; Concordância interexaminadores; Graduação histológica
• Palavras-chave em Inglês: Squamous cell carcinoma; Leukoplakia; Oral Epithelial Dysplasia; MAGE (Y-18); Immunohistochemistry; Interexaminer agreement; Histological grading
• Área do conhecimento CNPq: CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA
• Link de acesso: https://guaiaca.ufpel.edu.br/handle/123456789/2272

This study aims to evaluate the immunohistochemical expression of antibodie MAGE-(Y18) in potentially malignant oral lesions and malignant lesions in patients with or without factor risk, and also to check the interexaminers variability on histological classification of oral epithelial dysplasia. Paraffin-embedded samples of 20 cases of severe dysplasia/carcinoma in situ and 20 cases of intraoral squamous cell carcinoma (SCC) were used in the study, and in both groups the samples had been distributed between patients with and without other risk factors associated with the occurrence of injury (tobacco and alcohol). The positive immunohistochemical expression of MAGE(Y-18) was defined by a cytoplasmic staining pattern, and it was used a scoring system considering the homogeneity of the reaction. In order to verify the interexaminer variability when performing a histological classification of oral epithelial dysplasia, 75 cases of potentially malignant oral lesions were selected from a referral service in oral disease. Slides were read independently and blindly by three pathologists in two stages. In the first stage it was made available to examiners the slides stained with H & E along with the clinical information of each case, and pathologists had to classify the lesions: no dysplasia, mild dysplasia, moderate dysplasia, severe dysplasia or carcinoma in situ.In the second stage, it was not given access to clinical information to the examiners, and they had to classify slides into two categories: low risk (non-dysplastic lesions / mild dysplasia) and high risk (moderate or severe dysplasia / carcinoma in situ). . The results were positive in 4/20 PML and 17/20 SCC. Through the Kruskal-Wallis test, it was observed a statistically significant difference (p<0.05) between groups of CPB and the group of potentially malignant lesions (PML) without the risk factor. The Mann-Whitney test found a statistically significant difference between carcinomas and potentially malignant lesions (p<0.001). The Fisher Exact test showed no statistically significant difference between the lesions that had the same histological diagnosis when compared in subgroups of associated risk factor (p=1). Detection of MAGE antigen may be useful in identifying LPM that has a higher risk of progression to invasive SCC, but it seems to be unrelated to exposure to popular risk factors The agreement between the examiners and the gold standard ranged from low to moderate, regardless of the classification system that was used. In the first stage, the intraclass correlation coefficient showed a moderate agreement between examiners 1 and 3 (r = 0.479 and r = 0.544) and, a low agreement of the examiner 2 (r = 0.384). In the second phase, it was observed a moderate agreement between examiners 2 and 3 and the gold standard (k = 0.433 k = 0.422) and, a low concordance between the examiner 1 and the gold standard (k = 0.186).Taking into account that grading dysplasia is a subjective process and still there is no test that outperforms the histological observation on diagnosis of oral epithelial dysplasia, it is understood that the process of grading made by two or more examiners should be encouraged, in order to assist in defining more precisely the diagnostics