A systematic review and meta-analysis of comparative studies on the efficacy of extended pelvic lymph node dissection in patients with clinically localized prostatic carcinoma

Purpose Pelvic lymph node dissection (PLND) has been performed during radical prostatectomy in nearly all patients with clinically localized prostatic carcinoma (PCa), while the specific regions that needed to be removed demonstrated bifurcation among urologist. However, clinical studies comparing extended PLND (ePLND) with standard PLND (sPLND) and limited PLND (lPLND) reveal conflicting, or even opposing results. Methods All controlled trials comparing ePLND with sPLND or lPLND were identified through comprehensive searches of the PubMed, Cochrane Library and Embase databases. A systematic review and meta-analysis of these studies were then performed. Results Eighteen studies with a total of 8,914 patients were included. Regardless of being compared with sPLND or lPLND, ePLND significantly improved LN retrieval [ePLND vs. sPLND: weighted mean difference (WMD) 11.93, 95 % confidence interval (CI) 9.91–13.95, p < 0.00001; ePLND vs. lPLND: WMD 8.27, 95 % CI 3.53–13.01, p = 0.0006] and the detection of more LNs positive of metastasis [risk ratio (RR) 3.51, 95 % CI 2.14–5.75, p < 0.00001; RR 3.50, 95 % CI 2.20–5.55, p < 0.00001, respectively]. EPLND decreased the complication rate, but the differences were not statistically significant (RR 1.52, 95 % CI 0.87–2.65, p = 0.14; RR 1.52, 95 % CI 0.67–3.45, p = 0.32, respectively). Operating time, estimated blood loss, length of hospital stay and biochemical recurrence (BCR) were statistically insignificant between techniques. Conclusions ePLND shows benefits associated with increased LNs yield, LNs positivity, and safety, significantly with no risk of side effects. However, ePLND did not decrease BCR. Additional high-quality, well-designed randomized controlled trials and comparative studies with long-term follow-up results are required to define the optimal procedure for patients with clinically localized PCa.