Human Papillomavirus Prevalence in the Prostate and Seminal Vesicles: Does This Virus Have an Etiological Role in the Development of Prostate Cancer?

Human papillomavirus (HPV) is common in both sexes and is also detected in male urine and semen. However, its exact origin and its etiological role in the male genital tract remain unclear. Formalin-fixed paraffin-embedded tissues from 157 prostate cancer patients were analyzed. HPV-DNA was detected using a nested PCR reaction, and HPV genotyping was performed using flow-through hybridization for positive cases. In situ hybridization (ISH) was used to localize HPV-DNA, whereas HPV-E6/E7 mRNA ISH and p16INK4a immunohistochemistry were conducted on high-risk (HR) HPV-positive samples. HPV-DNA was detected in 9.6% of prostate cancers and 0% of seminal vesicles. HR-HPV was observed in 4.5% of the samples, with HPV44 being the most common genotype. HPV prevalence was significantly higher in patients with high-grade groups (GG 4–5). Among 15 HPV-positive cases, HPV-DNA was found in 9 cancerous and 10 non-cancerous lesions. E6/E7 mRNA was expressed in 6 of 7 HR-HPV-positive cases, while p16INK4a expression was weak or absent in all cases. HPV can infect prostate tissue and may contribute to carcinogenesis in some cases, but p16INK4a may not be a consistent surrogate for E7 expression.