Pelvic Lymphadenectomy May Not Improve Biochemical Recurrence-Free Survival in Patients with Prostate Cancer Treated with Robot-Assisted Radical Prostatectomy in Japan (The MSUG94 Group)

SIMPLE SUMMARY: This study evaluated the utility of pelvic lymph node dissection (PLND) in prostate cancer (PCa) patients undergoing robot-assisted radical prostatectomy (RARP). After propensity score matching, 1210 patients were enrolled and divided into two groups: those who underwent RARP without PLND (non-PLND group) and those who underwent PLND (PLND group). At the end of the follow-up period, no deaths due to PCa were identified in this study. Seventy-one patients (5.9%) had biochemical recurrence after RARP, and the 2-year biochemical recurrence-free survival (BRFS) rate was 95.0% for all patients, 95.8% for the non-PLND group and 94.3% for the PLND group (p = 0.855). For the all-risk group, there were no significant differences between patients who did and did not undergo PLND. Nevertheless, the results of the log-rank study indicate that PLND may be unnecessary for patients with PCa undergoing RARP. ABSTRACT: In this multicenter retrospective cohort study, we aimed to evaluate whether pelvic lymph node dissection (PLND) improved biochemical recurrence (BCR) in patients with prostate cancer (PCa) who underwent robot-assisted radical prostatectomy (RARP) in Japan. A multicenter retrospective cohort study of 3195 PCa patients undergoing RARP at nine institutions in Japan was conducted. Enrolled patients were divided into two groups: those who underwent RARP without PLND (non-PLND group) and those who underwent PLND (PLND group). The primary endpoint was biochemical recurrence-free survival (BRFS) in PCa patients who underwent PLND. We developed a propensity score analysis to reduce the effects of selection bias and potential confounding factors. Propensity score matching resulted in 1210 patients being enrolled in the study. The 2-year BRFS rate was 95.0% for all patients, 95.8% for the non-PLND group, and 94.3% for the PLND group (p = 0.855). For the all-risk group according to the National Comprehensive Cancer Network risk stratification, there were no significant differences between patients who did and did not undergo PLND. Based on the results of the log-rank study, PLND may be unnecessary for patients with PCa undergoing RARP.