Comparison of therapeutic features and oncologic outcome in patients with pN1 prostate cancer among robot-assisted, laparoscopic, or open radical prostatectomy

Objectives: To compare the therapeutic features and oncological outcomes of robot-assisted radical prostatectomy (RARP) with those of open radical prostatectomy (ORP) or laparoscopic radical prostatectomy (LRP) in lymph node (LN) positive prostate cancer patients in a retrospective observational multi-institutional study. Patients and methods: We evaluated the clinical results of 561 patients across 33 institutions who underwent RARP, LRP, or ORP and who were diagnosed with LN-positive prostate cancer during RP with pelvic LN dissection (PLND). We determined the following survival outcomes: metastasis-free survival, overall survival, cancer-specific survival, and biochemical recurrence-free survival. The Kaplan–Meier method, log-rank test, and Cox proportional hazards regression model were used to evaluate the effect of treatment on oncological outcomes. Statistical significance was set at P < 0.05. Results: There was no significant difference for any of the survival outcomes between the three surgical groups. However, RARP achieved a greater LN yield compared to that of ORP or LRP. When the extent of PLND was limited to the obturator LNs, the number of removed LNs (RLNs) was comparable between the three surgical groups. However, higher numbers of RLNs were achieved with RARP compared to the number of RLNs with ORP (P < 0.001) when PLND was extended to the external and/or internal iliac LNs. Conclusion: RARP, LRP, and ORP provided equal surgical outcomes for pN1 prostate cancer, and the prognosis was relatively good for all procedures. Increased numbers of RLNs may not necessarily affect the oncological outcome.