Probability of prostate cancer at various levels of per cent free prostate specific antigen in Japanese men with total PSA of 4.1-10.0 ng/ml

Estimates for the likelihood of prostate cancer at different levels of per cent free prostate specific antigen (PSA) were derived from experience with consecutive Japanese male patients with intermediate total PSA values who underwent ultrasound-guided biopsies and/or transurethral resection of the prostate. Receiver operating characteristic (ROC) curve analysis showed that in patients with a total PSA of 4.1–10.0 ng/ml, per cent free PSA identified those with prostate cancer better than did total PSA; per cent free PSA also proved superior in the subgroup whose glands appeared benign on palpation. The probabilities of prostate cancer at per cent free PSA values of ≤10.0, >10–15, >15–20, >20–26 and >26% were 58.3, 40.8, 25.3, 14.3 and 7.6%, respectively, when analyzed without regard to findings on palpation. In patients with palpably benign glands, the corresponding values were 55.3, 35.4, 19.6, 9.7, and 4.6%, respectively. These probabilities are lower than those reported in Western countries, probably reflecting both different patterns of practice and racial differences. Race-specific assessment is recommended before applying a clinical test.