Pelvic lymph node dissection at robot-assisted radical prostatectomy: Assessing utilization and nodal metastases within a statewide quality improvement consortium

Several guidelines recommend pelvic lymph node dissection (PLND) at robot-assisted radical prostatectomy (RARP) only when lymph node involvement (LN+) is >2%. Individual surgeon use of PLND is not well-known. We sought to examine variability in PLND performance and detection of LN+ across the Michigan Urological Surgery Improvement Collaborative. Data regarding all RARP (3/2012-9/2018) were prospectively collected, including patient and surgeon characteristics. Univariable and multivariable analyses of PLND rate and LN+ rate were performed. Among 9,751 men undergoing RARP, 79.8% had PLND performed (n = 7,781), of which 5.2% were LN+ (n = 404). In univariate and multivariable analyses, predictors of PLND included higher Prostate-Specific Antigen (PSA), biopsy Gleason grade (bGG), number of positive cores, and maximum core involvement at P < 0.05 for each. Higher PSA, cT stage, bGG, number of positive cores, and maximum core involvement predicted LN+ when PLND was performed (P < 0.05 for each). There was significant surgeon variation in the proportion of PLND performed at RARP, yet neither surgeon-annualized RARP volume nor % of PLND performed was associated with LN+ disease (P > 0.05). Grade was associated with PLND (60.0%, 77.6%, 91.0%, 97.3%, and 98.5%; P < 0.001) and LN+ (0.7%, 2.5%, 5.8%, 8.6%, and 19.9%; P < 0.001) for bGG 1,2,3,4,5, respectively. Maximum core involvement also strongly predicted LN+ with rates of 1.5%, 3.8%, and 9.4% for <35%, 35% to 65%, and >65%, respectively (P < 0.001). Nearly 80% of RARP in Michigan Urological Surgery Improvement Collaborative were performed with PLND, including 60% of bGG1 patients (with LN+ in only 0.7%), but significant variability exists between surgeons. Our data indicate limited benefit for favorable-risk CaP patients and support efforts to decrease PLND use going forward.