Objectives: To investigate pathological and oncological outcomes of obese patients who underwent robot-assisted radical prostatectomy (RARP) compared with laparoscopic radical prostatectomy (LRP) or open retropubic radical prostatectomy (RRP) since limited comparative data exist with regard to oncological and survival outcomes.
Methods: A total of 869 patients with body mass index ≥ 30 from two academic centers were identified. A total of 194 patients who underwent RARP were propensity score (PS) matched 1:1 to LRP or RRP cases. PS-matching variables included prostate-specific antigen (PSA), biopsy Gleason score, clinical stage, surgeon experience, and nerve-sparing technique. Predictors of positive surgical margins (PSMs) were analyzed using logistic regression. Predictors of recurrence-free survival (RFS) were analyzed within Cox regression models. Overall survival was compared with RFS using the log-rank test.
Results: Pathologic Gleason scores <7, =7, and >7 were found in 24.2, 63.6, and 11.7 % of patients, respectively. There were no statistically significant differences related to pathologic stage or lymph node metastases between surgical techniques. PSM for pT2 disease were observed in 22.9, 17.4, and 19.3 % of patients undergoing RARP, LRP, and RRP, respectively (not significantly different). Preoperative PSA and clinical stage cT2 disease were independently associated with PSM. There were no significant differences in mean 3-year RFS for RARP, LRP, and RRP (87.4, 91.0, and 85.7 %). Biopsy Gleason score >7, PSM, and clinical stage two were independent predictors of decreased RFS.
Conclusions: RARP demonstrates similar pathological and oncological results compared with LRP or RRP for obese patients.