RESUMO
Chinese men should have a higher prostate-specific antigen (PSA) "gray zone" than the traditional value of 2.5-10.0 ng ml-1 since the incidence of prostate cancer (PCa) in Chinese men is relative low. We hypothesized that PSA density (PSAD) could improve the rate of PCa detection in Chinese men with a PSA higher than the traditional PSA "gray zone." A total of 461 men with a PSA between 2.5 and 20.0 ng ml-1 , who had undergone prostatic biopsy at two Chinese centers were included in the analysis. The men were then further divided into groups with a PSA between 2.5-10.0 ng ml-1 and 10.1-20.0 ng ml-1 . Receiver operating characteristic (ROC) curve was used to evaluate the efficacy of PSA and PSAD for the diagnosis of PCa. In men with a PSA of 2.5-10.0 ng ml-1 or 10.1-20.0 ng ml-1 , the areas under the ROC curve were higher for PSAD than for PSA. This was consistent across both centers and the cohort overall. When the entire cohort was considered, the optimal PSAD cut-off for predicting PCa in men with a PSA of 2.5-10.0 ng ml-1 was 0.15 ng ml-1 ml-1 , with a sensitivity of 64.4% and specificity of 64.6%. The optimal cut-off for PSAD in men with a PSA of 10.1-20.0 ng ml-1 was 0.33 ng ml-1 ml-1 , with a sensitivity of 60.3% and specificity of 82.7%. PSAD can improve the effectiveness for PCa detection in Chinese men with a PSA of 2.5-10.0 ng ml-1 (traditional Western PSA "gray zone") and 10.1-20.0 ng ml-1 (Chinese PSA "gray zone").
