Total and free prostate-specific antigen indexes in prostate cancer screening: value and limitation for Japanese populations.

AIM To assess the efficacy and limitation of free/total prostate-specific antigen ratio (f/tPSA) at a single institution in Japan, focusing on the avoidance of pointless prostate biopsies. METHODS In total, 631 men between 44 and 93 years old (mean 69.8 years) with elevated PSA underwent power-Doppler ultrasoundgraphy-guided transrectal 10-core prostate biopsies at Niigata Cancer Center Hospital, and their histological features were investigated with total PSA (tPSA) and f/tPSA. RESULTS PCa was detected in 126 of 134 patients (94.3%) with tPSA of 26 ng/mL or higher. The detection rate was 59.4% for tPSA of 21-25 ng/mL, followed by 39.2% for 16-20 ng/mL, 30.0% for 11-15 ng/mL, 20.0% for 4.1-10 ng/mL and 7.6% for = or <4.0 ng/mL. f/tPSA of the PCa group was significantly lower than that of non-malignamt disorders in any tPSA ranges (mean 0.122 vs. 0.160, P<0.001). Receiver-operating characteristics analyses showed that f/tPSA (AUC:0.664) performed more valuably than tPSA (AUC:0.559) in patients with tPSA between 3.0-10 ng/mL (P<0.01). Although f/tPSA of 0.250 for the cut-off value might miss 1.8% PCa patients, it potentially spares 9.2% of unnecessary biopsies. CONCLUSION f/tPSA is more valuable compared with tPSA alone for the prediction of the occurrence of PCa. We recommend 0.250 as the cut-off value for f/tPSA in PCa screening for Asian men having so-called grey-zone tPSA.