Detection and typing of human papillomavirus DNA in penile carcinoma - Evidence for multiple independent pathways of penile carcinogenesis

To clarify the role of human papillomavirus (HPV) in penile cancer we evalu ated the prevalence of HPV DNA in different histological subtypes of penile carcinoma, dysplasia, and condyloma using a novel, sensitive SPF10 HPV pol ymerase chain reaction assay and a novel genotyping line probe assay, allow ing simultaneous identification of 25 different HPV types. Formalin-fixed, paraffin-embedded tissue samples were collected from the United States and Paraguay. HPV DNA was detected in 42% cases of penile carcinoma, 90% cases of dysplasia, and 100% cases of condyloma. There were significant differenc es in HPV prevalence in different histological cancer subtypes. Although ke ratinizing squamous cell carcinoma and verrucous carcinoma were positive fo r HPV DNA in only 34.9 and 33.3% of cases, respectively, HPV DNA was detect ed in 80% of basaloid and 100% of warty tumor subtypes. There was no signif icant difference in BPV prevalence between cases from Paraguay and the Unit ed States. In conclusion, the overall prevalence of BPV DNA in penile carci noma (42%) is lower than that in cervical carcinoma (similar to 100%) and s imilar to vulvar carcinoma (similar to 50%). In addition, specific histolog ical subtypes of penile cancer-basaloid and warty - are consistently associ ated with HPV, however, only a subset of keratinizing and verrucous penile carcinomas is positive for BTV DNA, and thus these two tumor groups seem to develop along different pathogenetic pathways.