The impact of robot-assisted radical prostatectomy on the use and extent of pelvic lymph node dissection in the "post-dissemination" period

Introduction: Previous series during the dissemination era of minimally invasive techniques for treatment of prostate cancer (PCa) showed a declining use of pelvic lymph node dissection (PLND). The aim of our study was to re-assess the impact of robot-assisted radical prostatectomy (RARP) on the utilization rate of PLND and its extent in the post-dissemination period.

Methods: Relying on the Surveillance Epidemiology and End Results (SEER) Medicare-linked database, 5804 patients with non-metastatic PCa undergoing open radical prostatectomy (ORP) or RARP between years 2008 and 2009 were identified. Uni- and multivariable logistic regression analyses tested the relationship between surgical approach (RARP vs. ORP) and: 1 - the rate of PLND (pNx vs. pN0-1); and 2 - the extent of PLND (limited vs. extended).

Results: Overall, 3357 (57.8%) patients underwent a PLND. The proportion of patients treated with PLND was significantly higher among ORP vs. RARP patients: 71.2 vs. 48.6%, respectively (P < 0.001). In addition, the median number of lymph nodes removed was significantly higher for patients treated with ORP vs. RARP: 5 vs. 4, respectively (P < 0.001). In multivariable analyses, ORP was associated with 2.7- and 1.3-fold higher odds of undergoing PLND and of receiving an extended PLND compared to RARP, respectively (both P ≤ 0.001). Stratified analyses according to disease risk classifications revealed similar trends.

Conclusions: In the post-dissemination era, RARP remains associated with a decreased use of PLND and suboptimum extent. Efforts should be made to improve guideline adherence in performing a PLND whenever indicated according to tumor aggressiveness, despite surgical approach.