Detecção de HPV (Papiloma vírus humano) em carcinoma epidermóide bucal: estudo caso-controle

Abstract

Oral cancer is one of the most common neoplasia in head and neck region, presenting high incidence in population and being responsible for high rates of deaths. Exposure to the products of tobacco and alcohol has been considered the major cause for the development of this disease. Though, some evidences indicate that Human Papillomavirus (HPV) can act in its genesis and progression. The objective of this work was to verify the frequency and the types of HPV in cases of oral squamous cell carcinomas and to verify its association with the disease. We accomplished a case-control study using 50 samples of squamous cell carcinomas that were diagnosed and treated in Federal University of Uberlândia, and a control group of 150 patients without cancer, matching from sex and age of the case patients. For identification and evaluation of the frequency of HPV in the different groups, the technique of Nested-PCR was used (Polimerase Chain Reaction, type Nested) for identification and typing of viral DNA. The reaction was developed using consensus primers MY09/MY11, following by the HPV typing through primers combined in eight multiplex kits, making possible the identification and typing of 40 types of HPV. The results showed that the sample of squamous cell carcinoma presented a relationship man:homan of 2,8:1, with a pick of cases for patients in the seventh decade of life. The frequency of HPV in cases was 22,0% (11 samples) and 9,3% in the controls (14 samples). The identified types in cases of squamous cell carcinoma were 16 and 31 (high risk) and 6, 44, 54 and 55 (low risk); in the patients of the control group were found types 33, 35, 45, 52, 62, 66 (high risk) and 42 (low risk). The univariate analysis showed association only among oral cancer and HPV and exposure to tobacco and alcohol. Though, the logistic regression evidenced a direct association among exposure to alcohol and cancer. No association was observed among age, sex, exposure to the products of tobacco and alcohol, location of the lesions (oropharynx and other), clinical stage of squamous cell carcinoma and the presence of HPV. These data allowed the conclusion that the development of oral cancer doesn't seem to be associated to the presence of HPV.