PSA may be elevated in non-malignant conditions such as
prostatitis and leads to unnecessary prostate needle biopsy. Urine prostatic exosomal
protein (PSEP) has been proved to be a promising
biomarker of prostatic
inflammation. The aim of this study is to determine the relationships between PSEP and the diagnosis of
prostate cancer (PCa), and their association with histologic prostatic
inflammation. Prostate needle biopsies from 674 patients were evaluated for the presence of histological
inflammation and PCa. The urine PSEP levels were measured using an
enzyme-linked
immunosorbent assay kit. 286 cases were diagnosed as PCa and prostatic
inflammation was observed in 33.7% of the biopsies. The presence of histological
inflammation was significantly associated with a lower PCa risk (P < 0.001). The urine PSEP levels was significantly lower in PCa patients compared to the controls (P = 0.003). When subanalyzed by PSA levels, the difference was more evident in cases with PSA 4-10 ng/ml (P = 0.039). The urine PSEP levels was correlated with histological
inflammation on prostate needle biopsy (P = 0.018, r = 0.12). Urine PSEP examination may be helpful to eliminate false positive PSA levels due to prostatic
inflammation and reduce unnecessary prostate needle biopsy in cases with PSA grey zone.