Clinical significance of limited and extended pelvic lymph node dissection during robot‐assisted radical prostatectomy for patients with localized prostate cancer: A retrospective, propensity score matching analysis

We investigated the diagnostic and therapeutic benefits of limited or extended pelvic lymph node dissection during a robot-assisted radical prostatectomy for localized prostate cancer.Diagnostic and therapeutic benefits were assessed according to the rates of pN1 and biochemical recurrence, respectively. The primary outcome was the biochemical recurrence-free rate, and secondary outcomes included the diagnostic and therapeutic benefits of pelvic lymph node dissection.A total of 534 patients were analyzed. Out of the 534 patients, 207 (38.8%) received limited pelvic lymph node dissection while 134 (25.1%) received extended dissection. There were 297 patients with a Briganti index ≥5%. Extended dissections yielded significantly more resected lymph nodes (p < 0.0001), and 72.2% of cases of pN1 were located outside the obturator. The incidence rate of pN1 was 6.1%, and performance of extended lymph node dissection was an independent predictor for pN1 (odds ratio 9.0, 95% confidence interval 2.5-33.1). The rate of biochemical recurrence was 14.9%, and Cox proportional hazards regression analysis of the propensity score matched population revealed that patients with high or very-high risk tended to benefit from limited lymph node dissection (hazard ratio 8.4, 95% confidence interval 0.8-82.3) while the therapeutic benefit of extended dissection was unclear by comparison.Extended pelvic lymph node dissection significantly improves diagnostic accuracy; however, the therapeutic benefit of pelvic lymph node dissection was not observed in this study.