Extended versus Standard Pelvic Lymph Node Dissection in Radical Prostatectomy on Oncological and Functional Outcomes: A Systematic Review and Meta-Analysis

We evaluated the effect of the extent of pelvic lymph node dissection (PLND) on oncological and functional outcomes in patients with intermediate- to high-risk prostate cancer (PCa) by conducting a systematic review and meta-analysis. Two independent researchers performed a systematic review of radical prostatectomy (RP) with extended PLND (ePLND), and RP with standard (sPLND) or limited PLND (lPLND) in patients with PCa using the PubMed, EMBASE, and Cochrane Library databases and using the terms 'prostatectomy', 'lymph node excision', and 'prostatic neoplasm'. The primary outcome was biochemical-free survival, which was analyzed by extracting survival data from the published Kaplan-Meier (KM) curves. In addition, we obtained summarized survival curves by reconstructing the KM data. Secondary outcomes of the recovery of erection and continence were also analyzed. Nine studies involving over 1554 patients were included, one of which was a randomized controlled trial. The pooled analysis showed a significant difference in biochemical recurrence between ePLND and sPLND (hazard ratio 0.71, 95% confidence interval 0.56-0.90, p = 0.005), with no significant between-study heterogeneity (I (2) = 37%). From the summary survival curves, it can be observed that the curves for the two groups diverged more and more as a function of time. From the analyses of functional outcomes including only three studies, no statistically significant differences in the recovery of erectile function and continence were observed. No evidence of significant publication bias was found. In patients with PCa, ePLND could be an oncological benefit; however, a functional compromise cannot be determined.