Is there a relationship between prostate volume and Gleason score?

To review the relationship between the Gleason grade and prostate volume in biopsy and radical prostatectomy (RP) specimens, and thus assess the hypothesis that smaller prostates have a greater incidence of high-grade tumours. We selected 390 patients who had RP at our institution, with a prostate-specific antigen (PSA) level of < 10 ng/mL and who had not had hormonal therapy. We retrospectively reviewed the data for transrectal ultrasonography (TRUS)-guided prostate biopsies from these patients and the RP specimens. Indications for biopsy included a PSA level of >= 4 ng/mL or an abnormal digital rectal examination. High-grade tumours were defined as having a Gleason score of >= 7. The TRUS volume was statistically related to the rate of high-grade tumours at biopsy and RP. On multivariate analyses, TRUS volume was a significant predictor of high-grade tumour for biopsy and RP specimens, with an inverse relationship between high-grade tumours and prostate volume for biopsy and RP specimens. Our data suggest that there is a relationship between the rate of high-grade tumours and prostate volume even in biopsy and RP specimens and it is not an artefact related to the biopsy.