Clinical Application of Free to Total PSA Ratio in Detection of Prostate Cancer in Korean Men : Lower Cut-off Value.
- Author:
Young Jae IM
1
;
Sung Joon HONG
;
Byung Ha CHUNG
Author Information
1. Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea. chung646@yumc.yonsei.ac.kr
- Publication Type:Original Article
- Keywords:
Prostatic neoplasm;
Biopsy;
Prostate-specific antigen
- MeSH:
Biopsy;
Humans;
Immunoassay;
Male;
Prostate*;
Prostate-Specific Antigen;
Prostatic Neoplasms*;
Sensitivity and Specificity
- From:Korean Journal of Urology
2004;45(8):753-757
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
Purpose: Whether the free to total prostate specific antigen (PSA) ratio (F/T PSA ratio) would enhance the detection of prostate cancer in Korean men with serum total PSA levels between 4 and 20ng/ml was evaluated. Materials and Methods: A total of 240 consecutive patients whose serum PSA levels were between 4 and 20ng/mul were enrolled in our recent two-year study. All patients underwent ultrasound-guided transrectal biopsies of the prostate gland. The F/T PSA ratio was measured using the Roche immunoassay (Roche Diagnostics GmbH, Manheim, Germany). Results: Of the 240 patients, 202 (84%) had a benign histology, while 38 (16%) had prostate cancer. The two patient groups were well matched for age. The mean F/T PSA ratio showed a statistically significant difference between the two groups: the benign histology group was 0.14 (0.04-0.37) and the prostate cancer group was 0.10 (0.08-0.20) (p<0.05). Out of the 183 patients in the group with PSA levels of 4-10ng/ml, the F/T PSA ratios were 0.14 and 0.11 in the benign histology (n=158) and prostate cancer (n=25) groups, respectively (p<0.05). From the 57 patients with the PSA level of 10-20ng/ml, the F/T PSA ratios were 0.14 and 0.10 in the benign histology (n=44) and prostate cancer (n=13) groups, respectively (p<0.05). Overall, when the cut-off value of the F/T PSA ratio was 0.10, the sensitivity and specificity were 75.0 and 76.5%, while for the a cut-off value of 0.15 they were 83.3 and 39.7%, respectively. Conclusions: Our data demonstrated the usefulness of the free to total PSA ratio in distinguishing benign prostate disease and cancer disease, hence eliminating unnecessary biopsies. It is recommended that a cut-off value for the F/T PSA ratio (0.10) be applied to Korean men; this is lower than the value used in Western countries.
