PSA-based parameters and their diagnostic performances in patients with prostate cancer and benign prostatic hyperplasia

Objective: The aim of this study is to evaluate the diagnostic performance of PSA- based parameters in prostate cancer (PCa) and benign prostatic hyperplasia (BPH) and to determine the relation between serum PSA and histopathological grade in PCa. Methods: This retrospective study includes data of 320 patients with PCa (n: 155) and BPH patients (n: 165). Serum PSA levels and Gleason scores of patients were determi- ned by examining the records of Clinical Biochemistry and Pathology Laboratory. We classified the patients according to total PSA (tPSA) levels to determine diagnostic per- formance of PSA-based parameters at different cut-off levels. Serum tPSA, free PSA (fPSA) and complexed PSA (cPSA) were analyzed with chemiluminometric method. Results: There were significant differences between BPH and PCa patients in tPSA, fPSA, cPSA and f/tPSA values (p<0.05) in whole group (WG). There were significant differences between BPH and PCa patients in cPSA and f/tPSA in group with tPSA<4 ng/mL (LG); in f/tPSA values in group with tPSA 4-10 ng/mL (intermediate group, IG). According to histopathological classification, all of the parameters except f/tPSA were significantly dif- ferent between groups in PCa (p<0.001). Significant positive correlations were found bet- ween Gleason scores and tPSA (r=0.577), fPSA (r=0.491) and cPSA (r=0.562) (p<0.001). Conclusion: We suggest the use of f/tPSA to improve the differentiation of BPH and PCa in IG. The best cut-off points for tPSA, fPSA, cPSA and f/tPSA were 4.0, 2.21, 3.16 ng/mL and 0.17 respectively. Based on the results of ROC analysis, a cut-off value of 0.17 for f/tPSA and 3.16 ng/mL for cPSA may be acceptable.