Differing prevalence of human papillomavirus RNA in penile dysplasias and carcinomas may reflect differing etiologies.

Penile intraepithelial neoplasias grade 3 (PIN 3) and penile carcinomas were examined for the presence of human papillomavirus (HPV) RNA transcripts by in situ hybridization using 125I-labeled RNA probes. Human papillomavirus transcripts were detected in all 10 PIN 3 lesions not associated with invasive malignant conditions but were present in only 29% of penile carcinomas (9 of 26 squamous cell carcinomas and none of 5 verrucous carcinomas). Human papillomavirus RNA-positive penile cancers were significantly more likely to exhibit adjacent PIN 3 lesions than were HPV-negative tumors, and PIN 3 lesions adjacent to tumors always contained the same HPV-RNA type as was present in the invasive tumor. The development of most penile cancers may be unrelated to HPV infection. Future epidemiologic studies of the role of sexually transmitted factors in the development of penile carcinoma should distinguish between HPV-positive and HPV-negative penile cancers.