Characterization of Human Papilloma Virus in Prostate Cancer Patients Undergoing Radical Prostatectomy—A Prospective Study of 140 Patients

Abstract

Introduction: The association between human papilloma virus (HPV) and the pathogenesis of prostate cancer (PCa) is still controversial. Existing studies often lack information about clinical risk factors, are limited by their retrospective design or only use a single detection method for HPV. Material and Methods: A total of 140 patients undergoing radical prostatectomy (RP) for PCa at the Department of Urology, Ludwig Maximilian University of Munich, Germany, were prospectively enrolled. Knowledge of HPV and sociodemographic parameters were assessed with questionnaires. The following methods were used for HPV detection: RP specimens were tested for HPV DNA by PCR. If HPV DNA was detected, an LCD-Array hybridization technique was used for HPV subtyping, and immunohistochemical staining for p16 was performed as a surrogate marker for HPV infection. Serological titers of HPV-16 L1 antibodies were measured using an HPV-16-specific immunoassay. Results: HPV DNA was detected in 9.3% (13/140) of RP specimens, with HPV-16 being the most predominantly detected subtype (5/13 = 39%). HPV-16 L1 antibody levels were below the limit of detection in 98% of patients (137/140). We found no significant difference between HPV PCR-positive (HPV+) and -negative (HPV-) patients in terms of HPV-16 antibody levels, history of HPV-associated diseases, level of education or marital status. Seventy-five percent of all PCa patients had never heard of HPV before. An acinar adenocarcinoma of the prostate was the most frequently detected histologic type in both HPV+ (100%) and HPV− (98%) patients (p = 0.86). HPV+ patients had fewer positive biopsy cores (3.5 vs. 5.8; p = 0.01) and a lower maximal tumor infiltration rate per core (37% vs. 57%; p = 0.03) compared to HPV- patients. However, when analyzing the whole prostate and the lymph nodes after RP, there were no significant differences in TNM stage, Gleason score or tumor volume between both groups. In a subgroup analysis of all high-risk HPV patients (n = 6), we found no significant differences in sociodemographic, clinical or histopathological parameters compared to HPV- or low-risk HPV+ patients. Conclusion: In our prospective study, we were not able to prove a clinically significant impact of HPV status on tumor characteristics in RP specimens. Most men with PCa had never heard of HPV, despite its proven causal association with other tumor entities.