The use of prostate specific antigen (PSA) density in detecting prostate cancer in Chinese men with PSA levels of 4-10 ng/mL

Abstract

Aim: To investigate the utility of prostate specific antigen density for detecting prostate cancer in men with serum PSA levels of 4-10 ng/mL.

Methods: Between January 2003 and November 2007, 237 men (aged 48-84 years, median 71) with total PSA levels of 4-10 ng/mL participated in a protocol for prostate cancer screening. Eligible patients were recommended for transrectal ultrasonography (TRUS)-guided prostate biopsies after measuring prostate volumes transrectally. The diagnostic value of PSA levels and the free-to-total PSA ratio (f/tPSA), PSA densities (PSAD) were compared using receiver operating characteristic analysis.

Results: Prostate cancer was diagnosed in 44 (18.6%) of the 237 men who had biopsies. There were significant differences between the groups in the prostate volumes determined by TRUS, PSAD, PSA levels and f/tPSA, whereas there was no significant difference in patient age. The area under the curve (AUC) of PSA (0.6786) and PSAD (0.717) was similar and significantly greater than that of f/tPSA (AUC 0.329). PSAD was a significantly better indicator of prostate cancer than f/tPSA. The sensitivity and specificity of PSA density at a cutoff of 0.134 ng/mL(2) was 90 and 33.7%, respectively.

Conclusion: PSAD was a better predictor of prostate cancer in Chinese men with PSA levels of 4-10 ng/mL, especially those who have had prior ultrasound-determined measurements of prostate volume. Our data suggest that different PSAD cutoffs may need to be defined for Chinese.

Fig. 1

ROC curves for the PSAD (TRUS, light blue line), f/tPSA (light green line) and PSA (red line). The AUC and the P values for the differences among each variable are shown in the text or Table 2