Introduction
Prostate cancer (PCa) is the second most common cancer in men. An estimated 1.1 million cases were diagnosed worldwide with PCa in 2012, accounting for 15% of the cancers diagnosed in men (1). For several years, the combination of the prostate-specific antigen (PSA) and digital rectal examination (DRE) has been used to diagnose PCa early. Catalona et al. suggested using a total PSA cutoff value of 4 ng/ml in order to recommend a prostate biopsy for diagnosing PCa (2). However, more than 20% of men diagnosed with PCa have PSA levels lower than 4 ng/ml and early detection in these patients could be expected to result in a higher probability of curative treatment (3). PSA is not specific for PCa; benign prostate hyperplasia, prostatitis, and other benign events can elevate PSA levels. Therefore, PSA has a low specificity for the diagnosis of PCa at 2.5-10 ng/ml (4). Free/total PSA ratio (f/t PSA), PSA density (PSAD), PSA velocity, and age-specific PSA used for early PCa detection in PSA levels of 2.5-10 ng/ml (3,5).
Many men with non-clinically significant PCa (N-CSPCa) will not progress to become symptomatic within their lifetime (6,7). If we can predict clinically significant PCa (CSPCa), we can prevent patients from unnecessary biopsies, overdiagnoses, and overtreatment. Some studies have shown that PSA, PSAD, f/t PSA can predict a Gleason score and CSPCa at the PSA level of 4-10 ng/dl (8,9). The purpose of this study was to determine whether PSAD and f/t PSA can predict CSPCa (Gleason ≥ 7) in patients diagnosed with prostate cancer on biopsy with a PSA level of 2.5-10 ng/ml or not.