Utilization of Pelvic Lymph Node Dissection for Patients With Low-Risk Prostate Cancer Treated With Robot-Assisted Radical Prostatectomy.

INTRODUCTION: Pelvic lymph node dissection (PLND) is not recommended for low-risk prostate cancer (PCa) patients. However, the rate of PLND in this population is unknown.

METHODS: We queried the National Cancer Data Base for PCa patients who underwent robot-assisted radical prostatectomy from 2010 to 2013 and stratified them by D'Amico risk classification. We identified the frequency of PLND in low-risk patients and identified factors associated with receipt of PLND. Further, we determined the number of lymph nodes evaluated (quality) and proportion of patients with detected nodal metastatic disease (utility) in each risk group.

RESULTS: Of 51,971 patients with low-risk PCa who underwent robot-assisted radical prostatectomy, 19,059 (36.7%) received PLND. Predictors of PLND in low-risk patients included rural residence (odds ratio [OR], 1.157; 95% confidence interval [CI], 1.009-1.327), treatment at an academic center (OR, 1.492; 95% CI 1.188-1.874), and high-volume facility (OR, 1.327; 95% CI, 1.078-1.633). The mean number of lymph nodes obtained in low-risk patients was lower than in intermediate/high-risk patients (4.74 vs. 5.86, P < .0001). Lymph node positivity was identified in 0.4% of low-risk patients and 4.6% of intermediate/high-risk patients.

CONCLUSION: While PLND is not recommended for low-risk PCa by clinical practice guidelines, it was performed frequently (36.7%) in a large hospital-based data set. PLND in this population was of lower quality (nodal yield) and had less utility of detecting nodal metastatic disease than PLND in intermediate/high-risk PCa. Treatment at a high-volume or academic center was associated with increased use of PLND. Reasons for the variation in practice patterns should be investigated to improve the value of PCa care.