Predictive Value of PSA Density in Pathological Discordance Terms in Patients who Undergo Robotic Surgery for Low-risk Prostate Cancer: An Analytic Cross-sectional Study of a Tertiary Reference Center

Abstract

Aim: Pathological discordance between biopsy and radical prostatectomy (RP) remains a critical issue in determining appropriate treatment for prostate cancer (PCa). With this study, we aimed to evaluate the role of prostate specific antigen (PSA) density in predicting pathological discordance in low-risk PCa. Methods: Data from 95 patients who underwent RP for low-risk PCa with Prostate Imaging Reporting and Data System 1-2 on multiparametric magnetic resonance imaging (MRI) were retrospectively analyzed in this cross-sectional study conducted between January and December 2023. The patients were divided into two groups according on biopsy and robotic-assisted laparoscopic prostatectomy pathology. The “compatible group” was defined as patients with no difference in International Society of Urological Pathology grade and tumor stage, other patients were defined as “incompatible group”. The cut-off value for PSA density to predict the presence of pathological discordance was calculated by receiver operating-characteristic curve. Results: Thirty eight (40%) patients were in the compatible group. No difference was found in serum PSA value between the groups (p=0.440), and a significant difference was found in prostate volume and PSA density (p=0.04 and p=0.001, respectively). The predictive cut-off value of PSA density was calculated as 0.088 ng/mL/cc (area under the curve: 0.729) (p<0.001). The sensitivity, specificity, positive and negative predictive values for this 0.088 ng/mL/cc value were 75.4%, 63.2%, 67.2% and 70.3%, respectively. Conclusion: Prostate specific antigen density was found to have good performance in predicting pathological discordance in low-risk PCa patients with no pathological lesions detected by multiparametric MRI.

Keywords

• biopsy
• prostatic neoplasms
• prostatectomy
• prostate-specific antigen
• psa density
• robotics