Extent of pelvic lymph node dissection improves early oncological outcomes for patients with high-risk prostate cancer without lymph node involvement after robot-assisted radical prostatectomy

Background We investigated the effect of the extent of pelvic lymph node dissection (LND) on biochemical recurrence (BCR) in patients with prostate cancer (PCa) without lymph node involvement (LNI) treated with robot-assisted radical prostatectomy (RARP). Methods We retrospectively analyzed data from 378 patients who underwent RARP with LND at our hospital between October 2010 and June 2019. The BCR-free survival rate was determined using Kaplan–Meier analysis, and Cox regression analysis was used to investigate BCR prognostic factors. The total score calculated from the D’Amico risk classification and the percentage of positive biopsy cores were used for analysis. Patients were classified into 3 BCR risk groups (low risk: 0–3 points, intermediate risk: 4–5 points, and high risk: 6–8 points). Results Limited LND was performed in 161 patients (42.6%), extended LND in 217 patients (57.4%), and BCR was confirmed in 66 patients (17.5%) after RARP. Both univariate and multivariate analyses showed no significant difference in the association between the extent of LND and BCR. The Kaplan–Meier curve for BCR generated using our risk classification for patients with PCa without LNI showed no significant association between the extent of LND and BCR in the low-risk group ( p = 0.790). A significantly improved BCR-free survival was observed in the extended LND group among patients with PCa at intermediate risk or higher ( p