Robotic radical prostatectomy: analysis of midterm pathologic and oncologic outcomes: A historical series from a high-volume center.

Background: Identifying predictors of positive surgical margins (PSM) and biochemical recurrence (BCR) after radical prostatectomy (RP) may assist clinicians in formulating prognosis. Aim of the study was to report the midterm oncologic outcomes, to identify the risk factors for PSM and BCR and assess the impact of the PSM on BCR-free survival following robot-assisted laparoscopic radical prostatectomy (RALP).

Methods: From 2005 to 2010, 1679 consecutive patients underwent transperitoneal RALP. Data was retrospectively collected by an independent statistical company and analyzed in 2014. Median postoperative follow-up was 33.5 mo. BCR was defined as any detectable serum prostate-specific antigen (PSA) ≥ 0.2 ng/mL in two consecutive measurements. BCR-free survival was estimated using the Kaplan-Meier method. Univariate and multivariate analysis were applied to identify risk factors for PSM and BCR.

Results: In pN0/pNx cancers, pathologic stage was pT2 in 1186 patients (71.8%), pT3 in 455 patients (27.6%), and pT4 in 11 patients (0.6%). PSM rate was 17.4% and 36.9% of pT2 and pT3 cancers, respectively. Pathologic Gleason score was < 7, = 7 and > 7 in 42.1%, 53% and 4.9% of the patients, respectively. Overall BCR-free survival was 73.1% at 5 years; the 5-year BCR-free survival was 87.9% for pT2 with negative surgical margins. PSA, Gleason score (both bioptic and pathologic), pathologic stage (pT) and surgeon's volume were significant independent predictors of PSM. PSA, pathologic Gleason score, pT and PSM were significant independent predictors of BCR-free survival. Seminal vesicle-sparing, nerve-sparing approach and the extent of nerve-sparing (intra vs interfascial dissection) did not negatively affect margin status or BCR rates.

Conclusions: PSMs are a predictor of BCR. Being the only modifiable factor influencing the PSM rate, surgical experience is confirmed as a key factor for high-quality oncologic outcomes.