Background: The aim of the present study was to assess the possible etiologic role of human papillomaviruses (HPV) in bladder tumors.
Methods: Forty-two fresh biopsy specimens from different grades and stages of bladder tumor cases and 10 normal bladder mucosa biopsies were studied. Specimens were analyzed by polymerase chain reaction (PCR) with HPV-specific general primer set for the detection of viral DNA. Polymerase chain reaction-positive samples were also tested with HPV 16- and 18-specific primers by the same method.
Results: We found two samples (4.8%) containing HPV DNA among the TaG1 bladder tumors. All other specimens, including the control group, were found to be negative by PCR. Neither of the two HPV-positive patients had immune deficiency and/or genital wars. Human papillomavirus 16 was detected by type-specific primers in one sample, but the other HPV-positive sample could not be typed.
Conclusions: The low prevalence of HPV in this and many previous studies does not support an etiologic role of HPV in bladder carcinogenesis. We detected the virus in two early stage tumors, but none was detected in the high-grade samples. However, to clarify the positivity of HPV in these occasional cases, future studies must be designed by using in situ PCR techniques, including samples from tumors and normal bladder mucosa from the same patient.