Between-subject variations of transition zone epithelial volume and serum PSA levels in men with benign prostatic hyperplasia.

Purpose: We verified if the measure of transition zone epithelial volume (TZepiV) could be a valid predictor of serum PSA value in men with benign prostatic hyperplasia (BPH).

Materials And Methods: Between January 2005 and July 2008, a total of 90 patients undergoing transvesical suprapubic adenomectomy for sintomatic BPH were enrolled. In case of an elevated PSA level (above 4 ng/ml) or abnormal digital rectal examination, systematic multisite biopsies were performed preoperatively to rule out prostate cancer. We have examined PSA levels before and after open surgery, TZ weight as measured by the pathologist and TZepiV by multiplying percentage of epithelium of a single biopsy core with the weight of adenoma. Means, Spearman correlation coefficients and percent change were calculated for all variables and intervals.

Results: The mean serum PSA decreased from 4.8 ng/ml preoperatively to 0.5 ng/ml postoperatively. The mean decrease in PSA was 90% (range 70-99%).The mean weight of enucleated adenoma was 67 gr.(range 18-201) and the TZepiV was 7.7 ml (0.3-28.4). Overall, both TZ volume and TZepiV were correlated to PSA value with TZepiV representing the most predictive variable for PSA (r = 0.54 P = 0.002 vs. r = 0.26 P = 0.02). When we analyzed different ranges of PSA values, only TZepiV was always significantly proportional to PSA.

Conclusions: Ninety percentage of serum PSA level comes from TZ in range of 0.01-0.17 ng/ml/gr. In presence of equal BPH volumes, the amount of epithelium can be different and it is the main determinant in PSA increase. Thus, TZ epithelial volume could represent a new useful clinical tool able to increase the specificity of PSA in the diagnosis of prostate cancer.