Reevaluating the therapeutic role of extended lymph node dissection in the era of robot-assisted radical prostatectomy

Abstract

To elucidate the real-world oncological outcomes of robot-assisted radical prostatectomy (RARP) and effectiveness of extended pelvic lymph node dissection (ext-LDN) in the RARP era. Data from 8 194 patients who underwent RARP, including age, clinical T stage, prostate-specific antigen (PSA) before prostate cancer diagnosis (initial PSA), follow-up years, biopsied specimen grade group (GG), and whether they underwent lymph node dissection or not and presurgical androgen deprivation therapy, were recorded. Oncological outcomes among three risk groups (low, intermediate, and poor risks) were analyzed using Kaplan-Meier curves. In intermediate and poor risk cohorts, PSA failure-free, clinical recurrence-free, castration-resistant prostate cancer (CRPC)-free survival, and overall survival (OS) were compared between the ext-LDN groups and no or limited lymph node dissection (no-ltd-LND) groups before and after propensity matching for initial PSA, clinical stage, GG, and androgen deprivation therapy. Four survivals (PSA failure-free, clinical recurrence-free, CRPC-free survival, and OS) were noted among the three risk groups that generally reflected the risks. In comparison between ext-LDN and no-ltd-LND groups, propensity matching matched four factors. No significant difference was observed in the four survivals with or without ext-LDN. In the intermediate-risk, high-risk, and locally advanced cohorts (cT3-4), similar analyses were performed as the subanalyses; no significant difference was observed in the three subanalyses. We showed survival differences among the risk groups and that extended pelvic lymph node dissection has no oncological effectiveness using the largest patient cohort in the literature.