Utilization of pelvic lymph node dissection for low-risk prostate cancer.

Abstract

86 Background: National guidelines suggest against pelvic lymph node dissection (PLND) for patients with low-risk prostate cancer (PCa). However, the actuarial rate of PLND in this population is unknown. This study aimed to characterize the use of PLND in contemporary cohort of men with low-risk PCa undergoing robotic assisted radical prostatectomy (RARP). Methods: The National Cancer Database was queried for PCa patients who underwent RARP from 2010 to 2013. Patients who underwent PLND were identified and patient clinicodemographic and hospital characteristics were abstracted. The primary outcome measure was receipt of PLND. Secondary outcome measures included number of lymph nodes evaluated and number of lymph nodes positive for cancer. Unadjusted and multivariate regression analyses were conducted to identify predictors of receipt of PLND. Analysis of clustered data was employed to account for hospital-level correlation in utilization. Results: Of 51,971 patients with low-risk PCa who underwent RARP, 19,059 (36.7%) received PLND. Lymph node positivity was identified in 0.4% of low-risk patients and 4.6% of intermediate/high risk patients. Predictors of PLND in low-risk patients included rural residence (OR 1.157), treatment at academic institutions (OR 1.492) or high-volume (OR 1.327) facilities. Mean number of lymph nodes obtained in low-risk patients was lower than in intermediate- or high-risk patients (4.74 vs 5.86, P < 0.0001). In multivariate analysis, black race was associated with significantly fewer lymph nodes retrieved. Intermediate or high risk PCa; rural residence; and treatment at an academic, high-volume, or West region facility were independently associated with a higher yield of retrieved lymph nodes. Conclusions: PLND is performed for greater than one-third of low-risk PCa patients undergoing RARP in this large hospital-based data set. Our study demonstrated a low likelihood (0.4%) of detecting nodal metastasis in this population, thus validating the national recommendations against PLND. Rural residence and treatment at high-volume and academic centers are associated with receipt of PLND. Reasons for the variation in practice patterns should be investigated to improve the quality of PCa care.