Use of percent free prostate-specific antigen as a predictor of the pathological features of clinically localized prostate cancer

Purpose: To evaluate the usefulness of percent free serum prostate-specific antigen (PSA) as a predictor of the pathological features of prostate canc er. Materials and Methods: Total and free serum PSA were measured preoperativel y in 220 consecutive patients with clinically localized prostate cancer who underwent radical prostatectomy, Organ-confined disease and favorable path ology were considered as the outcomes for this study. Results: Percent free serum PSA was not able to predict these outcomes in t he overall population. However, it could significantly predict favorable pa thology in a subset of patients in whom digital rectal examination (DRE) wa s normal and total PSA ranged from 4.1 to 10 ng/ml, A 11% cutoff provided a significant distribution with an odds ratio of 2.8 (95% confidence interva l 1.1-7.0), a positive predictive value of 63.3% and a negative predictive value of 46.3%, Conclusions: According to these results, we suggest that percent free PSA m ay provide additional information for the staging of clinically localized p rostate cancer. However, the reference population for its usefulness would be those patients with normal DRE and total PSA between 4.1 and 10 ng/ml. C opyright (C) 2000 S. Karger AG. Basel.