Interactions between benign prostatic hyperplasia (BPH) and prostate cancer in large prostates: a retrospective data review

Purpose To study the interaction between benign prostatic hyperplasia (BPH) and prostate cancer (PCa). Methods In this study, we performed a chart review of a cohort of 448 biopsy naive men. These men received a multi-core biopsy at our institution due to increased prostate-specific antigen (PSA) serum levels (>4 ng/ml) and/or suspicious findings on digital rectal examination in the years between 2008 and 2013. Utilizing PSA and transrectal ultrasound (TRUS) prostate volume, we obtained the PSA density (PSAD) for each individual. PSAD was calculated by dividing serum PSA concentration by TRUS prostate volume. Results Large prostates >65 g may secrete enough PSA to have a PSAD above the suggested cutoff of 0.15, yet 50 % patients have no histologic evidence of PCa, whereas prostates <35 g and an elevated PSAD of above 0.15 will have histologic evidence of PCa 70 % of the time. Conclusions These results suggest that BPH in large prostates may be protective of PCa. The interaction of the different prostate zones, in particular the transition zone and peripheral zone, may play a significant role in the phenomenon observed in this study. However, sampling error may introduce bias that 12-16 core biopsies in larger prostates may be more likely missing the cancer lesion.