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 determined by examining the records of Clinical Biochemistry and Pathology Laboratory. We classified the patients according to total PSA (tPSA) levels to determine diagnostic performance 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 different between groups in PCa (p<0.001). Significant positive correlations were found between 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.