Estudo da etiologia do câncer genital masculino: prevalência do papilomavírus humano (HPV), vírus Epstein-barr (EBV) e poliomavírus de células Merkel (MCPYV)

Introduction: The genital infection by the human papillomavirus (HPV) can result in a sexually transmitted disease (STD) associated with precursor lesions for carcinogenesis in the genital tract. In recent years, evidence was accumulated defining human papillomavirus (HPV) as the etiologic agent of cervical cancer, however, the etiology of penile cancer is still open and in lack of studies. Although HPV is an important factor for malignization, other oncogenic factors may be associated with the initiation or progression of the tissue malignancy process, such as the Epstein-Barr virus (EBV) and, particularly, the Merkel cell polyomavirus (MCPyV), which detection is achieved in both healthy and lesioned epithelium, and, under appropriate conditions, might present an oncogenic behavior within the epithelial tissue. This study aims to contribute to the epidemiologic knowledge regarding the prevalence of these viruses in malignant lesions of the male genital tract. Objectives: To investigate the presence of MCPyV, EBV and HPV in penile malignant lesions; to genotype HPV when present; to quantify the MCPyV when present; and to correlate HPV types and lesion degree with the presence and viral load of MCPyV and EBV. Methods: A total of 112 penile cancer samples were collected in a cross-sectional study. The detection methodology consisted of: 1 - Detecting the presence of HPV DNA by the PCR technique with generic primers; 2 - Genotyping the HPV through PCR with specific primers and by using Microarray assay; 3 - Detecting and quantifying the MCPyV DNA by the Nested PCR and real-time PCR, respectively; 4 - Detecting, quantifying and genotyping EBV by PCR. 5 – Correlate the histopathology, tumour invasiveness, and the dispersion of malignant cells by the lymphonodes, with the presence of the studied viruses Results: The HPV prevalence was 57.1% (64) while MCPyV was detected in 3.5% (4) of the samples. EBV was detected in 47.3% (53), and EBV1 was the most prevalent genotype. All patients positive for MCPyV were also positive for HPV, and we described an unprecedented case of multi-infection by all three viruses in a penile squamous cells carcinoma. This was the first report in the literature in this kind of penile lesion. Conclusion: The prevalence of HPV and EBV infections indicates an important role of these viruses in the penile tissue malignancy. The role of the viral infection was significant within the multifactorial etiology of penile cancer. There was statistical significance between the lesion invasiveness and the presence of the EBV1, high-risk HPV and HPV/EBV infection. We have found no statistical correlation between the lymphonodic dispersion, nor the histopathology grade, with the presence of the studied viruses. The prevalence of MCPyV was found not significant, but its presence indicates the opportunistic infectious potential of this virus, and suggests the importance of further studies and epidemiological surveillance.