Human Papillomavirus (HPV) Infection As an Emerging Risk Factor in Prostate Cancer

Abstract

Background: Epidemiologic investigations confirm that prostate tissue is prone to sexually transmitted infection and human papilloma virus (HPV) is the most common sexually transmitted infection. Owing to the controversy on the role of HPV infection in prostate carcinogenesis, it is appropriate to determine and validate the prevalence of HPV infection in a controlled prospective study, and its role in prostate carcinogenesis. It is crucial to investigate the prognostic impact of HPV infection in prostate cancer from a clinical point of view. Aim: The overall aim of our research is to address the possibility of using therapeutic interventions against HPV infection in young boys to prevent the development of prostate cancer in their older age. Establishment of clinical importance of HPV infection in prostate cancer and its prognostic impact for overall survival. Methods: The prostate cancer tissue specimens were obtained from Sahlgrenska University Hospital, Sahlgrenska Academy (SA), Gothenburg, Sweden. The exclusion criteria included patients undergoing any preoperative radiation or chemotherapy. Only histopathologically confirmed cases were processed for DNA, protein and RNA extraction. Histopathological grades and clinical staging was evaluated by pathologists using the Gleason scoring system for prostate cancer. The study is approved by the ethics committee of the institute. High molecular-weight genomic DNA was isolated from tumor/control tissue samples and were subjected to PCR genotyping for detection of the viral DNA. Cases and controls was compared using univariate methods. An independent t-test was performed for the comparison of clinicopathological parameters. Results: The pilot study identified HPV infection in advanced grade of prostate cancer cases in Sweden. HPV infection was identified in 57% of the prostate cancer cases with advanced pathologic grade in Swedish men compared with 11% in the normal controls. The investigation comprised of detailed analysis of the correlation between the clinical parameters and HPV genotyping. Conclusion: The research investigation substantiates the clinical significance of HPV infection in prostate carcinogenesis that has been underestimated till date. The research investigation was funded by Swedish Research Council (Vetenskaprådet) Grant no. 2015-06705.