Significance of Serum Concentration of Free and Total Prostate Specific Antigen in Benign Prostatic Hyperplasia and Prostate Cancer

Seo, Hyeok Jun; Park, Hyung Min; Kwon, Tae Gyun; Chung, Sung Kwang; Kim, Bup Wan; Lee, Jaetae

Abstract

PURPOSE: This study was performed to investigate whether the free to total PSA ratio(F/T PSA ratio) offers a better discriminant for the detection of patient with prostatic cancer(CaP) and those with benign prostatic hyperplasia(BPH) than serum total PSA alone.
MATERIALS AND METHODS
From September 1996 to February 1999, free and total PSA levels were measured on frozen sera samples of 154 men with BPH and 46 with CaP using immunoradiometric assay.
RESULTS
In all subjects, the mean total PSA was significantly higher in CaP group(72.59+/-66.58ng/ml) than BPH group(3.12+/-4.10ng/ml). The mean PSAD was significantly higher in CaP group(1.64+/-1.86) than BPH group(0.08+/-0.01). The mean F/T PSA ratio was significantly lower in CaP group(0.19+/-0.07) than BPH group(0.30+/-0.13). Among 41 subjects whose total PSA were between 4-20ng/ml, the mean PSAD was significantly higher in CaP group(0.37+/-0.16) than BPH group(0.17+/-0.07), but the mean F/T PSA ratio was not significantly different between CaP(0.19+/-0.10) and BPH group(0.25+/-0.13). By comparing the sensitivity and specificity of total PSA alone, PSAD and F/T PSA ratio on receiver operating characteristic(ROC) curve in all subjects and subjects with total PSA between 4-20ng/ml, F/T PSA ratio had no superiority than total PSA alone and PSAD for. discrimination between CaP and BPH.
CONCLUSIONS
We suggest that the F/T PSA ratio is not superior to total PSA alone and PSAD in the detection of prostatic cancer, and further evaluation of the usefulness of F/T PSA ratio should be required.