Predictors of positive surgical margins at open and robot-assisted laparoscopic radical prostatectomy: a single surgeon series.

Robot-assisted laparoscopic radical prostatectomy (RALRP), increasingly used to treat localized prostate cancer, has advantages over open radical prostatectomy (ORP) in terms of reduced bleeding and quicker convalescence. However, debate continues over whether RALRP provides superior or at least equivalent surgical outcomes. This study compares positive surgical margins (+SM), as a surrogate for long-term cancer control, at RALRP and ORP performed by a single experienced surgeon during the process of taking up RALRP. 400 consecutive patients undergoing surgery for prostate cancer under a single surgeon (DW) between November 1999 and July 2009 were studied. Prior to July 2005, all patients underwent ORP; after this date, most patients were treated by RALRP. Data were collected by retrospective chart review and analysed independently of the treating surgeon. +SM were defined as the presence of cancer at an inked surface. Overall, 23 (11.5%) of 200 patients undergoing RALRP had +SM, compared to 40 (20.0%) of 200 patients undergoing ORP (P < 0.05). On univariate logistic regression analysis, in addition to surgical approach (odds ratio [OR] = 1.92), patient age (OR = 1.05), pathologic stage (OR = 3.93) and specimen Gleason (GS) score (OR = 1.86) were significant predictors of +SM. On multivariate analysis, surgical approach, p-stage and specimen GS remained significant predictors of +SM. RALRP is associated with lower rates of +SM compared to ORP, even after adjusting for other known risk factors. Of note, the RALRP in this study were part of the surgeon's learning curve.