High Risk Human Papilloma Virus DNA Detected in Primary Squamous Cell Carcinoma of Urinary Bladder
Jennifer Chapman-Fredericks, Maureen Cioffi-Lavina, Molly Accola, William Rehrauer, Monica Garcia-Buitrago, Carmen Gomez-Fernandez, Parvin Ganjei-Azar, Richard Cote, Merce Jorda. University of Miami, Jackson Memorail Hospital, Sylvester Cancer Center, Miami, FL; University of Wisconsin School of Medicine, Madison, WI
Background: The oncogenic role of Human Papillomavirus (HPV) in many epithelial neoplasms has been well documented, however its role in bladder carcinogenesis is controversial. We previously reported that 37% of primary urinary bladder squamous cell carcinomas (SCC) demonstrate diffuse p16 immunoreactivity. P16 has been used as a surrogate marker for HPV infection, but p16 expression may be due to non HPV-related mechanisms. We attempted to detect HPV DNA in the tumor cells of p16 positive primary bladder SCC using in situ hybridization (ISH) and a signal amplification Invader assay followed by genome sequencing.
Design: Fourteen cases of p16 positive primary SCC of the bladder (8 male, 6 female) were reviewed. Analysis for High Risk (HR) HPV was performed in all cases using both 16/18 ISH and Invader assay. Screening for HR HPV and identification of HPV types 16/ 18 was accomplished using Cervista™ HPV HR and Hologic Cervista™ HPV 16/18 reagents, respectively. HR HPV positive samples were then amplified with type specific primers and products of amplification were DNA sequenced using Big Dye version 2.0 on an Applied Biosystems instrument.
Results: HPV 16/18 ISH was negative in all cases. However, 3 of 14 cases (21.4%) were positive for HR HPV using the Cervista™ detection method. HPV DNA was amplified and sequenced in all 3 positive cases using type specific primers. Two of the positive cases demonstrated HPV 16 genotype using Cervista™ HPV 16/18 reagents, and this finding was confirmed by amplification and sequencing. The genotype of the third positive case could not be determined using the Cervista™ HPV 16/18 method but by sequencing it was found to be HPV type 35. The 3 HPV DNA cases were all from female patients ages 52, 64 and 70 years.
Conclusions: HR HPV DNA was identified in a 21% of p16 positive bladder SCC by two independent methods (Invader signal amplification and HPV DNA sequencing). This study confirms that HR HPV is present in a subset of primary bladder SCC. Since ISH method failed to detect the presence of HR HPV in some cases, it appears that ISH can not be used as the sole method for detection of HPV. The fact that all cases used in this study were known to express p16 by IHC but only 21.4% contained HR HPV DNA, suggests that other non-HPV related mechanisms may contribute to p16 expression in bladder SCC. Thus, p16 should not be used as a surrogate marker for the presence of HPV in this setting.
Category: Genitourinary (including renal tumors)
Tuesday, March 20, 2012 1:00 PM
Poster Session IV # 97, Tuesday Afternoon