HPV detection in oral leukoplakia and oral squamous cell carcinoma / "Detecção do HPV em leucoplasias e carcinomas epidermóides orais"

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

It is still highly controversial whether HPV can be considered an aetiological or risk factor for the development of malignant/premalignant lesions of the oral cavity. There is an agreement that there is at least quantitative evidence to relate HPV and oral carcinogenesis, since in general the studies find a proportional relation between degree of malignancy and HPV infection ? the prevalence of HPV in squamous cell carcinoma is higher than in premalignant lesions which is higher than in normal mucosa. It is known, however, that premalignant lesions can present several degrees of epithelial dysplasia, which does not allow analyzing them as a group. Hence, in this context, the aim of this study was to analyze more refinedly the relation between degree of malignancy and infection by HPV by means of viral DNA detection in oral leucoplakias and oral squamous cell carcinomas, dividing the group of premalignant lesions according to the degree of epithelial dysplasia within the lesion. Fifty cases diagnosed as oral leucoplakia and oral squamous cell carcinoma were selected and divided into 5 groups: leucoplakia with no dysplasia, leucoplakia with mild dysplasia, leucoplakia with moderate dysplasia, leucoplakia with severe dysplasia and squamous cell carcinoma. Clinical data regarding patients? age and gender and anatomic site of the lesion were observed and the presence of HPV DNA was assessed using CSA-ISH method with a wide spectrum probe. In positive cases to the wide spectrum probe, genotyping with specific probes to HPV types 6/11, 16/18 and 31/33 was performed. The overall prevalence of HPV infection was 24%, which is higher than the reported for oral normal mucosa, which stands around 1 and 2%. Results show a discrete proportional relation between degree of malignancy and HPV infection indexes found in leucoplakia with no dysplasia, leucoplakia with dysplasia and squamous cell carcinoma, but with no statistical significance. Dividing the group of leucoplakia with dysplasia, this relation of proportion was not observed. In genotyping, most cases were positive to the probe for types 16/18, of high oncogenic potential, and cases positive to the probe for types 6/11, of low oncogenic potential, were only found within groups of lower degrees of malignancy. Only one case was positive for two specific probes (16/18 and 31/33). There was no correlation between clinical features and HPV infection. These results suggest that HPV detection is not related to the degree of malignancy in these lesions. Nevertheless, the fact that the prevalence in these cases, which were all malignant/premalignant lesions, was higher than the one found in oral normal mucosa, and that the high-risk types of HPV were the most frequently found within the positive cases does not allow excluding HPV as a risk factor in oral carcinogenesis.

ASSUNTO(S)

oral carcinogenesis carcinogênese oral in situ hybridization leucoplasia squamous cell carcinoma carcinoma epidermóide hibridização in situ leukoplakia

ACESSO AO ARTIGO

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