Free / total prostate specific antigen ratio for prostate cancer detection: a prospective blind study.
BACKGROUND
We conducted this prospective study to evaluate the ability of the percentage of free PSA (% fit PSA) to improve the specificity of prostate cancer (PC) detection.


METHODS
Seven hundred and eighty-five patients with serum PSA levels between 4 and 25 ng/ml underwent sextant biopsies of the prostate. The % f/t PSA was analyzed for the sensitivity, specificity and positive predictive values.


RESULTS
The mean % f/t PSA of the 169 patients with PC was 18.0 +/- 7.7 and was significantly (p < 0.0001) lower than that of the 616 patients who had histologically benign biopsy specimens, with a mean % f/t PSA of 26.6 +/- 9.7. Using 30% f/t PSA as the cut-off eliminated 34.4 % of the negative biopsies while still detecting 93.4% of the carcinomas.


CONCLUSIONS
The optimal cut-off value of 30% f/t PSA may be applied as reference using the Cis bio international assay for PC detection.
Yang
Chi-Rei
CR
Division of Urology, Department of Surgery, Taichung Veterans General Hospital, School of Medicine, National Yang-Ming University, Taiwan, ROC.
Su
Chung-Knang
CK
Chiu
Kun-Yuan
KY
Ho
Hao-Chung
HC
Ou
Yen-Chuan
YC
Cheng
Cheng-Li
CL
Lee
Huei
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood*; D011469:Prostatic Diseases / Q000097:blood / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014463:Ultrasonography
D017430:Prostate-Specific Antigen