The value of PSA, free-to-total PSA ratio and PSA density in the prediction of pathologic stage for clinically localized prostate cancer

Abstract

Objective: The ability of prostate-specific antigen (PSA), free/total PSA and PSA density to predict the pathologic stage in prostate cancer has not been clear yet. In this study, we evaluated the value of PSA subgroups in the prediction of pathologic stage after radical prostatectomy.

Methods: A total of 42 subjects 55-78-years-old who underwent radical retropubic prostatectomy were included in the study. Preoperative PSA, free/total PSA and PSA density (PSAD) values were compared according to the pathologic stages of radical prostatectomy specimens. Receiver operating characteristics (ROC) curves were measured for each parameter.

Results: The clinical stage that was estimated for all patients was between T1N0M0 and T2bN0M0. Pathologic examination revealed organ-confined disease in 18 patients. The area under curve (AUC) for organ confinement was 0.553 for PSA, 0.446 for free/total PSA ratio and 0.706 for PSAD. Cut-off values providing the best sensitivity and specificity in ROC analysis for PSA, free/total PSA and PSAD were 7.1, 0.15, and 0.17, respectively (likelihood ratio: 0.9, 1 and 2). The positive predictive values at these cut-off values were 0.54, 0.56, and 0.70, respectively. Only PSAD cut-off values was found statistically borderline significant for predicting organ-confined disease.

Conclusion: While PSAD is more helpful than PSA and free/total PSA ratio for prediction of organ-confined disease, none of these parameters are significant predictor of pathologic stage for clinically localized prostate cancer.