Relationship between serum prostate-specific antigen and prostate volume in men with benign prostatic hyperplasia from multicenter study

Abstract

Purpose: Prostate volume (PV) is a key predictor of both the progression and response to medical therapy in patients with benign prostatic hyperplasia (BPH). Prostate-specific antigen (PSA) has been studied as a proxy marker for the estimation of the total PV in a predominantly Caucasian patient population. If the PV of Korean men is smaller than that of Caucasian men, the PSA-PV of Korean men may be different from those of the other races. The relationship between the PSA and PV was evaluated in Korean men. Materials and methods: Patients with lower urinary tract symptoms and BPH, aged between 50 and 79 years, between 1999 and 2004, were enrolled in this multicentered study. IPSS, PSA, uroflowmetry and TRUS measurements were performed on all patients. Men with a PSA greater than 10ng/ml were excluded to reduce the likelihood of including occult prostate cancer cases. Those with suspicious findings on digital rectal examination and serum PSA were biopsied to rule out prostate cancer. Results: The analysis included 5,716 patients, with a mean age 64.3 years, and mean baseline PV and PSA of 36.9ml and 2.4ng/ml, respectively. The PV and serum PSA have an age-dependent log-linear relationship. Older men tend to have a steeper rate of increase in their PV with increasing serum PSA. Receiver operating characteristic (ROC) curves were constructed to evaluate the ability of the serum PSA to predict the threshold of the PV in men with BPH. The ROC curve analysis revealed that the PSA had good predictive value for various PV cutoff points (30, 40 and 50ml). Conclusions: The PSA-PV relationship in Korean men was similar to that in Caucasians. However, Korean men have a lower PSA and smaller PV than Caucasians. Approximate age-specific criteria for detecting Korean men with PV exceeding 40ml are: PSA >1.3ng/ml, >1.7ng/ml and >2.0 ng/ml for men with BPH in their 50s, 60s and 70s, respectively.