Extended Versus Limited Pelvic Lymph Node Dissection During Radical Prostatectomy for Intermediate- and High-risk Prostate Cancer: Early Oncological Outcomes from a Randomized Phase 3 Trial

Abstract

BackgroundThe role of extended pelvic lymph node dissection (EPLND) in the surgical management of prostate cancer (PCa) patients remains controversial, mainly because of a lack of randomized controlled trials (RCTs). ObjectiveTo determine whether EPLND has better oncological outcomes than limited PLND (LPLND. Design, setting and participantsThis was a prospective, single-center phase 3 trial in patients with intermediate- or high-risk clinically localized PCa. InterventionRandomization (1:1) to LPLND (obturator nodes) or EPLND (obturator, external iliac, internal iliac, common iliac, and presacral nodes) bilaterally. Outcome measurements and statistical analysisThe primary endpoint was biochemical recurrence–free survival (BRFS). Secondary outcomes were metastasis-free survival (MFS), cancer-specific survival (CSS), and histopathological findings. The trial was designed to show a minimal 15% advantage in 5-yr BRFS by EPLND. Results and limitationsIn total, 300 patients were randomized from May 2012 to December 2016 (150 LPLND and 150 EPLND). The median BRFS was 61.4 mo in the LPLND group and not reached in the EPLND group (hazard ratio [HR] 0.91, 95% confidence interval [CI] 0.63–1.32; p = 0.6). Median MFS was not reached in either group (HR 0.57, 95% CI 0.17–1.8; p = 0.3). CSS data were not available because no patient died from PCa before the cutoff date. In exploratory subgroup analysis, patients with preoperative biopsy International Society of Urological Pathology (ISUP) grade groups 3–5 who were allocated to EPLND had better BRFS (HR 0.33, 95% CI 0.14–0.74, interaction p = 0.007). The short follow-up and surgeon heterogeneity are limitations to this study. ConclusionThis RCT confirms that EPLND provides better pathological staging, while differences in early oncological outcomes were not demonstrated. Our subgroup analysis suggests a potential BCRFS benefit in patients diagnosed with ISUP grade groups 3–5; however, these findings should be considered hypothesis-generating and further RCTs with larger cohorts and longer follow up are necessary to better define the role of EPLND during RP. Patient summaryIn this study, we investigated early outcomes in prostate cancer patients undergoing prostatectomy according to the anatomic extent of lymph node resection. We found that extended removal of lymph nodes did not reduce biochemical recurrence of prostate cancer in the expected range.