Imunoexpressão das proteínas Catepsina B e E-caderina nas leucoplasias de prega vocal: correlação clínica, epidemiológica e histopatológica

• Ano de defesa: 2010
• Autor(a) principal: Amorim Filho, Francisco de Souza [UNIFESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Caderinas; Catepsina B; Prega vocal/patologia; Leucoplasia/epidemiologia; Leucoplasia/patologia; Neoplasias laríngeas
• Link de acesso: http://repositorio.unifesp.br/handle/11600/9728

Introduction: Early identification of vocal fold leukoplakia with risk for malignancy is a controversial subject and difficult in terms of diagnosis. Histological changes that may predispose to this irreversible malignant transformation remain as undefined lesions in the larynx. With the analysis of immunohistochemical parameters and the discovery of a biological marker able to identify these early lesions, a more effective early treatment can be provided, which can result in the preservation of phonatory organ. Objective: To analyze the immunohistochemical protein expression of cathepsin B-and ECadherin in leukoplakia of the vocal fold and correlate them with clinical data, epidemiology and prognosis of the disease. Method: We retrospectively evaluated 32 patients with leukoplakia of the vocal folds in the Institute of Larynx- city of Sao Paulo- diagnosed through laryngoscopy and treated with surgery during 2000 to 2004. Patients were divided into two groups according to histological results, Group A (Low Grade, n = 16) and Group B (High Grade, n = 16). Slides added by anti-cathepsin-B and anti-E-cadherin were obtained from paraffin blocks for subsequent reading of markers through Imagna- ImageLab processing. The quantitative expression of cathepsin B-and Ecadherin was evaluated according to the coloration intensity and tissue distribution. The expression index (EI) of each marker was correlated to patient´s lifestyle (use of tobacco and alcohol), signs of gastroesophageal reflux disease and local recurrence of the lesion in two separate groups and among all patients. Results: In the descriptive analysis, the vocal fold leukoplakia showed more intensity in men who had frequent habit of smoking and alcohol consumption. These patients had high levels suggestive of signs of gastroesophageal reflux disease and local recurrence of the lesion after initial treatment. Statistical analysis comparing the levels of expression (IE) of the markers between the groups (A and B), patients with local recurrence in Group B (High Grade) had higher IE for cathepsin-B. In the statistical analysis of IE markers among all patients without histological differentiation, the IE of cathepsin-B was higher among smokers and those with no signs suggestive of reflux. In the same analysis, E-cadherin was higher in all patients with local recurrence. Conclusion: Smoking patients who have moderate or severe dysplasia, carcinoma in situ and high levels of cathepsin-B were more susceptible to local recurrence of disease. Those with signs suggestive of gastroesophageal reflux disease had lower IE of cathepsin-B, independent of histologic differentiation. The increase in cathepsin-B expression, for high grade lesions group, indicates this protein as a possible marker of aggressiveness to leukoplastic vocal cord lesions. The rate of expression of Ecadherin is shown as a potential marker for recurrence of leukoplastic vocal fold lesions.