Análise comparativa da proliferação celular entre carcinomas de células escamosas orais HPV-positivos e HPV-negativos

Abstract

Background: Oral Squamous Cell Carcinoma (OSCC) is the most common malignant tumor in the mouth, and the human papillomavirus (HPV) has been hardly studied as a possible etiologic agent. Objectives: The aim of this study was to compare the rates of cell proliferation in HPV-positive and HPV-negative OSCC, using the immunohistochemical antibody Ki-67. Material and method: The sample consisted of 11 cases HPV-positive OSCC (10 cases infected with HPV-18 and 1 case infected with HPV-16 and 18) and 13 cases HPV-negative OSCCs, previously analyzed regarding the presence or absence of HPV, as well as the viral type, using PCR (primers GP5+/GP6+) and dot blot hybridization, respectively. Immunohistochemical study was performed by streptoavidin-biotin technique with antibody against nuclear protein Ki-67. Results: The mean of positivity index of the HPV-positive OSCC (17.7%) was greater than HPV-negative OSCC (14.2%), however the statistic analysis showed that standard deviation in both groups was very high, almost equal the mean (14% and 9.5%, respectively). The Mann-Whitney non-parametric statistic test disclosed that there wasn’t a significantly statistical difference between the groups. Discussion: Similar studies to these are few and they are not concordant in demonstrating a bigger tumoral proliferative activity in those cases infected by HPV in relation to those not infected, either through the analysis of the protein expression related to the cellular cycle as in the direct analysis of the tumoral proliferative fraction. Conclusion: There were not differences in the rates of cell proliferation between the HPV-positive and HPV-negative grups.