Investigation of the Possible Cytopathological Effect of Human Papillomavirus Infection on p-16INK4a Overexpressed Urothelial Carcinomas ofthe Bladder in the Urine

Background and objectives: Human papillomavirus (HPV) is well-known as the etiological agent for uterine cervical cancer or carcinoma of the oropharynx, anus and vulva. However, the cytopathologic effect of the HPV infection in urinary bladder tumors has rarely been reported. The present study has been carried out to search for cytopathologic differences between HPV positive and negative cases with urothelial carcinoma. Methods: We examined 91 specimens from 63 patients who underwent transurethral resection or biopsy for papillary urothelial carcinomas between May 2010 and September 2012. p-16INK4a expression was evaluated by immunohistochemistry. Detection of HPV DNA was carried out by in situ hybridization on formalin-fixed, paraffinembedded tissue sections. Urine smears were compared cytomorphologically between HPV-positive and HPVnegative cases. Results: p-16INK4a overexpression was detected in 29 cases (31.9%, 29/91). Of them, HPV DNA was detected in 11 cases. No significant cytopathologic differences were found in tumor cells when HPV-positive and HPV-negative cases were compared. Conclusion: HPV could be detected in urothelial carcinomas of the urinary bladder. There were no significant differences in cytopathologic features of urine smears between HPV-positive and HPV-negative cases with urothelial carcinomas. These results suggest that HPV infection in urinary tract does not add substantial clinically relevant importance to the carcinogenesis and cytomorphology of urothelial carcinomas.