Objectives. Prostate-specific antigen (PSA) is produced exclusively in the prostate gland and is currently the most useful clinical marker for the detection of prostate cancer. In this report, we examine whether serum PSA is also a predictor of important benign prostatic hyperplasia (BPH)-related outcomes, acute urinary retention (AUR), and the need for BPH-related surgery.

Methods. Three thousand forty men were treated with either placebo or finasteride in a double-blind, randomized study of 4-year duration. Serum PSA was measured at baseline, and baseline prostate volume was measured in a 10% subset of 312 men. Probabilities and cumulative incidences of AUR and BPH-related surgery, as well as reduction in risk of events with finasteride, were calculated for the entire patient population, stratified by treatment assignment, baseline serum PSA, and prostate volume.

Results. The risk of either needing BPH-related surgery or developing AUR ranged from 8.9% to 22.0% during the 4 years in placebo-treated patients stratified by increasing prostate volume and from 7.8% to 19.9% when stratified by increasing serum PSA. In comparison with symptom scores, flow rates, and residual urine volume, receiver operating characteristic curve analyses showed that serum PSA and prostate volume were the most powerful predictors of spontaneous AUR in placebo-treated patients (area under the curve 0.70 and 0.81, respectively). Finasteride treatment reduced the relative risk of needing surgery or developing AUR by 50% to 74% and by 43% to 60% when stratified by increasing prostate volume and serum PSA, respectively.

Conclusions. Serum PSA and prostate volume are powerful predictors of the risk of AUR and the need for BPH-related surgery in men with BPH. Knowledge of baseline serum PSA and/or prostate volume are useful tools to aid physicians and decision makers in predicting the risk of BPH-related outcomes and choosing therapy for BPH.