Estudo comparativo da imunomarcação da p53 em carcinomas epidermóides bucais de sítios anatômicos diferentes

Abstract

The role of TP53 tumor supressor gene alterations and its product, p53protein, has been well established in oral carcinogenesis process. Squamous cell carcinoma is the most common malignancy of the oral cavity, the tongue being the most frequent affected site. It was investigated, by means of immunohistochemistry using DO-1 monoclonal antibody, p53 protein expression in 43 tissue samples of oral squamous cell carcinomas from different anatomical sites. Patients mean age was 58,6 years, being 35 (81,4%) male and 8 (18,6%) female patients. Thirty-three lesions (76,8%) showed positivity for p53 and 10 lesions were p53-negatives (23,2%). p53 expression mean index was 48,37%. No statistically significant differences between p53 expression mean indexes and the different anatomical sites analysed were found.Similarly, no differences were found when comparing tongue lesions with the other anatomical sites, grouped or singly. Equally, p53 expression was not associated to the other clinicopathological variables studied: sex, age and histological malignancy grading of the invasive tumor front (HMG-ITF). Of 41/43 lesions available for assessing HMG-ITF, 14 (34,15%) were well differentiated,17 (41,46%) moderately, and 10(24,39%) were poorly differentiated lesions. p53 expression was seen in 11/14 (78,6%) well differentiated lesions, in 15/17 (88,2%) moderately differentiated lesions, and in 6/10 (60%) of poorly differentiated lesions. These results suggest that it might not exist any differences between oral cavity different anatomical sites, as well as sex and age of patients, in relation to p53 mechanisms. Moreover, p53 expression in squamous cellcarcinomas of the tongue does not reflect the higher tumor aggressiveness reported in this anatomical site. A direct relationship between p53 expression and cellular differentiation grade could not be established as well.