Percent of free serum prostate-specific antigen and histological findings in patients undergoing open prostatectomy for benign prostatic hyperplasia

Purpose: To determine which pathologic features of the surgical specimen in men undergoing open prostatectomy for benign prostatic hyperplasia (BPH) c orrelate with preoperative and postoperative total, free prostate-specific antigen (PSA) levels and the free-to-total PSA ratio. Methods: Forty-four p atients, undergoing open prostatectomy for BPH without evidence of prostate cancer in systematic biopsies and clinical prostatitis, were included in t his prospective study. Each prostatectomy specimen was weighed and each sli de was evaluated for inflammation (acute prostatitis, chronic-active prosta titis and chronic-inactive prostatitis), prostatic intraepithelial neoplasi a, transitional/squamous metaplasia, cystic ductal dilation, leiomyoma-rese mbling stromal cell proliferation, leakage of prostatic secretion, infarcti on and prostatic calculi. Results: The mean preoperative (and postoperative ) total PSA and free PSA levels were 6.1 +/- 4.3 (1.14 +/- 0.87) and 1.7 +/ - 1.6 (0.24 +/- 0.19) ng/ml, respectively. The mean prostatic and transitio n zone volume was 83.9 +/- 28.4 and 55.4 +/- 27.6 cm(3), respectively. Both total PSA and free PSA levels were correlated with total gland volume (p = 0.0001; p = 0.002) and the volume of the surgical specimen (p = 0.003; p < 0.05) and, upon stepwise logistic analysis, patients with a total gland vo lume of <50 cm(3) had an odds ratio of 11 (CI 1.6-71.3) for having a free-t o-total ratio of <18%. No minimal change pathology or prostatic inflammatio n were associated with preoperative total or free PSA levels. The free-to-t otal PSA ratio was higher in the group of patients with histologically acut e and moderate to severe chronic-active prostatitis (mean ratio 27 +/- 12%) than in patients with chronic-inactive prostatitis and minimal chronic-act ive prostatitis (mean ratio 0.19 +/- 13%; p = 0.05), showing an odds ratio of 5 (CI 1.1-22.1) for having a free-to-total PSA ratio of <18%. Conclusion s: Prostate volume and, in particular, transition zone volume seem to influ ence both free a nd total PSA levels in men with BPH. The free-to-total PSA ratio seems to be influenced by the presence of histological prostatitis i n the surgical specimen. In particular, patients with a prostate volume of <50 cm3 and an inactive form of prostatitis seem to have a relatively highe r risk of having a free-to-total PSA ratio of <18%. Copyright (C) 1999 S. K arser AG, Basel.