Predictors of biochemical recurrence after Retzius-sparing robot-assisted radical prostatectomy: Analysis of 359 cases with a median follow-up period of 26 months.

Objectives: Our aim was to evaluate the predictors of biochemical recurrence after Retzius-sparing robot-assisted radical prostatectomy.

Methods: The study cohort consisted of 359 consecutive non-metastatic prostate cancer patients who underwent Retzius-sparing robot-assisted radical prostatectomy between November 2012 and January 2016. According to the National Comprehensive Cancer Network prostate cancer risk classification, 164 patients (45.7%) had high- or very high-risk prostate cancer. No patient received adjuvant therapy until documented biochemical recurrence. Biochemical recurrence-free survival was estimated using the Kaplan-Meier method. Univariable and multivariable Cox proportional hazards regression models were used to determine variables predictive of biochemical recurrence.

Results: The median follow-up period was 26 months (interquartile range 19-38 months). The overall biochemical recurrence rate was 14.8%, and the median time to biochemical recurrence was 11 months (interquartile range 6-22 months). The 3-year biochemical recurrence-free survival probability was 71.2%, 72.1%, 88.7%, 82.3% and 95.7% in very high-, high-, intermediate-, low- and very low-risk prostate cancer, respectively (log-rank, P < 0.001). On multivariable analysis, preoperative prostate-specific antigen (hazard ratio 1.03, 95% confidence interval 1.02-1.04; P < 0.0001), percentage of maximum core involvement on biopsy (hazard ratio 1.02, 95% confidence interval 1.01-1.03; P = 0.029) and clinical stage ≥T3a (hazard ratio 2.12, 95% confidence interval 1.02-4.39; P = 0.043) were predictors of biochemical recurrence, whereas pathological Gleason score ≥8 (hazard ratio 5.63, 95% confidence interval 1.62-19.61; P = 0.007) and pathological tumor volume (hazard ratio 1.08, 95% confidence interval 1.04-1.20; P < 0.001) were the main pathological predictors of biochemical recurrence.

Conclusions: Retzius-sparing robot-assisted radical prostatectomy confers effective biochemical recurrence control at the mid-term follow-up period. Preoperative prostate-specific antigen, advanced clinical stage and higher Gleason score were important predictors of biochemical recurrence after Retzius-sparing robot-assisted radical prostatectomy. Long-term oncological safety still needs to be established.