REVIEW ON THE SIMULTANEOUS DETERMINATION OF TOTAL PROSTATE-SPECIFIC ANTIGEN AND FREE PROSTATE-SPECIFIC ANTIGEN

BACKGROUND. The total prostate-specific antigen (t-PSA) in serum measu red by PSA assays represents the sum of free (f-PSA) and PSA complexed with alpha 1-antichymotrypsin. The f-PSA/t-PSA (F/T) ratio in prostat e cancer (PCA) patients is lower than in patients suffering from benig n prostatic hyperplasia (BPH). This review summarizes the currrent lit erature on the clinical relevance of measurement of the F/T PSA ratio. METHODS. Discussed are: physiology of PSA, assays for t-PSA and FIT r atio, factors which bias the F/T PSA ratio, use of F/T PSA ratio in th e detection of PCA, correlation with histological features, and pathol ogical stage. RESULTS. Using the F/T ratio in the intermediate t-PSA r ange, a reduction of approximately 30% in biopsies can be accomplished in the detection of prostate cancer. CONCLUSIONS. The F/T PSA ratio c ould become a valuable tool in the differentiation of BPH from PCA. To accomplish this goal, an international standardization not only for t he t-PSA measurement but also for the F/T PSA ratio must be a priority for manufacturers of PSA assays. (C) 1996 Wiley-Liss, Inc.