Extended vs non-extended pelvic lymph node dissection and their influence on recurrence-free survival in patients undergoing radical cystectomy for bladder cancer: a systematic review and meta-analysis of comparative studies.

OBJECTIVE: To compare extended pelvic lymph node dissection (ePLND) with non-extended pelvic lymph node dissection (non-ePLND) and assess their influence on recurrence-free survival (RFS) in patients undergoing radical cystectomy for bladder cancer.

METHODS: Through a comprehensive search of the PubMed, Embase and Cochrane Library databases in September 2012, we performed a systematic review and cumulative meta-analysis of all comparative studies assessing the extent of pelvic lymph node dissection (PLND) and its influence on RFS.

RESULTS: Six studies with a total of 2824 patients were identified. Overall analysis showed a significantly better RFS rate in patients who had undergone ePLND than in those who had undergone non-ePLND (hazard ratio [HR]: 0.65; P < 0.001). A subgroup analysis found that, compared with non-ePLND, ePLND was associated with a better RFS rate for both patients with negative lymph nodes (HR: 0.68; P = 0.007) and those with positive lymph nodes (HR: 0.58; P < 0.001). When stratified by pathological T stage, ePLND provided additional RFS benefits for patients with pT3-4 disease (HR: 0.61; P < 0.001), but not for patients with ≤pT2 disease (HR: 0.95; P = 0.81).

CONCLUSIONS: The results of this meta-analysis indicate that ePLND provides a RFS benefit compared with non-ePLND. On subgroup analysis, ePLND provides better RFS not only for patients who had positive lymph nodes and pT3-4 disease, but also for patients with negative lymph nodes. Two randomized controlled trials on ePLND vs non-ePLND are awaited which should provide more clinically meaningful results.