Evaluation of Biochemical Recurrence-free Survival after Radical Prostatectomy by Cancer of the Prostate Risk Assessment Post-Surgical (CAPRA-S) Score

Background: The cancer of the prostate risk assessment (CAPRA) score has been defined to predict prostatecancer recurrence based on the pre-clinical data, then pathological data have also been incorporated. Thus,CAPRA post-surgical (CAPRA-S) score has been developed based on six criteria (prostate specific antigen(PSA) at diagnosis, pathological Gleason score, and information on surgical margin, seminal vesicle invasion,extracapsular extension and lymph node involvement) for the prediction of post-surgical recurrences. In thepresent study, biochemical recurrence (BCR)-free probabilities after open retropubic radical prostatectomy (RP)were evaluated by the CAPRA-S scoring system and its three-risk level model. Materials and
Methods: CAPRA-Sscores (0-12) of our 240 radical prostatectomies performed between January 2000-May 2011 were calculated.Patients were distributed into CAPRA-S score groups and also into three-risk groups as low, intermediate andhigh. BCR-free probabilities were assessed and compared using Kaplan-Meier analysis and Cox proportionalhazards regression. Ability of CAPRA-S in BCR detection was evaluated by concordance index (c-index).
Results:BCR was present in 41 of total 240 patients (17.1%) and the mean follow-up time was 51.7 ± 33.0 months. MeanBCR-free survival time was 98.3 months (95% CI: 92.3-104.2). Of the patients in low, intermediate and highrisk groups, 5.4%, 22.0% and 58.8% had BCR, respectively and the difference among the three groups wassignificant (P = 0.0001). C-indices of CAPRA-S score and three-risk groups for detecting BCR-free probabilitiesin 5-yr were 0.87 and 0.81, respectively.
Conclusions: Both CAPRA-S score and its three-risk level model wellpredicted BCR after RP with high c-index levels in our center. Therefore, it is a clinically reliable post-operativerisk stratifier and disease recurrence predictor for prostate cancer.