Purpose: Although asymptomatic prostatitis is the most common noncancer diagnosis as demonstrated histologically by biopsies, screening and identification before biopsy remain unclear. In this study we prospectively evaluate the efficacy of examination of post-prostatic massage urine for prediction of asymptomatic prostatitis in biopsies.
Materials and methods: A total of 161 consecutive men 50 to 80 years old with serum prostate specific antigen 4.1 to 10.0 ng/ml, normal digital rectal examination, no evidence of clinical prostatitis or urinary tract infection, who underwent 8 or 10-core prostate biopsies under transrectal ultrasonography guidance were included in the study. Immediate pre-biopsy leukocyte count in post-prostatic massage urine was determined per high power field (400 x). We selected 5, 7 and 10 leukocytes per high power field as cutoffs, and urine was examined for prediction of histological prostatitis.
Results: Histological diagnosis was prostatitis, benign prostatic hyperplasia and prostate cancer in 66 (41.0%), 63 (39.1%) and 32 (19.9%) patients, respectively. The mean number of leukocytes and percentage of positive post-prostatic massage urine microscopy for all cutoffs were significantly higher in subjects with prostatitis than in those without prostatitis (p <0.0001). Histological prostatitis was predicted most accurately by the 5 leukocyte cutoff (sensitivity 68.2%, specificity 82.1% and area under the receiver operating characteristics curve 0.75).
Conclusions: In asymptomatic men with mild increases of prostate specific antigen histological evidence of prostatic inflammation is common. The leukocyte count in post-prostatic massage urine appears to be useful for screening of this condition before biopsy. Our data suggest that 10 leukocytes per high power field in post-prostatic massage urine, the usually applied cutoff, may be too high for the definition of prostatic inflammation.