Cherullo, Edward E.

89 Background: Lymph node counts have been proposed as a quality metric for patients undergoing radical prostatectomy (RP) and pelvic lymph node dissection (PLND). It is unclear whether surgical approach and hospital characteristics independently determine the number of lymph nodes removed at PLND. Therefore, we assessed the variation in lymph node counts from a population-based cohort of patients undergoing surgery for intermediate and high-risk prostate cancer. Methods: Using the National Cancer Database, we identified all surgically treated patients diagnosed with pre-treatment intermediate or high-risk prostate cancer from 2010 to 2011. The primary outcome was the number of lymph nodes retrieved at the time of RP. Generalized estimating equations were used to assess for differences in the adjusted number of lymph nodes retrieved after accounting for patient and hospital characteristics and surgical approach. Results: Overall, 35,876 patients were diagnosed with intermediate (61.2%) and high-risk (38.8%) prostate cancer and underwent RP and PLND. On multivariable analysis, open radical prostatectomy (ORP) and high volume and academic hospitals were independently associated with greater lymph node counts compared to robotic-assisted radical prostatectomy (RARP) and medium/low and community hospitals, respectively (all p<0.001). After adjusting for patient and hospital variables, higher adjusted lymph nodes counts were observed for ORP compared to RARP (7.1 vs. 6.1; p<0.001). Adjusted counts were also higher for high volume compared to medium/low volume hospitals (7.8 vs. 5.9; p<0.001), and academic compared to community hospitals (7.3 vs. 5.6; p<0.001). Conclusions: Among patients with aggressive prostate cancer treated with RP and PLND, lymph node counts varied by surgical approach and hospital characteristics.