The impact of the extent of lymphadenectomy on oncologic outcomes in patients undergoing radical cystectomy for bladder cancer: a systematic review

Context: Controversy exists regarding the therapeutic value of lymphadenectomy (LND) in patients undergoing radical cystectomy (RC) for muscle-invasive bladder cancer (MIBC).

Objective: To systematically review the relevant literature assessing the impact of LND on oncologic and perioperative outcomes in patients undergoing RC for MIBC.

Evidence acquisition: Medline, Medline In-Process, Embase, the Cochrane Central Register of Controlled Trials, and the Latin American and Caribbean Center on Health Sciences Information (LILACS) were searched up to December 2013. Comparative studies reporting on no LND, limited LND (L-LND), standard LND (S-LND), extended LND (E-LND), superextended LND (SE-LND), and oncologic and perioperative outcomes were included. Risk-of-bias and confounding assessments were performed.

Evidence synthesis: Twenty-three studies reporting on 19,793 patients were included. All but one study were retrospective. Planned meta-analyses were not possible because of study heterogeneity; therefore, data were synthesized narratively. There were high risks of bias and confounding across most studies as well as extreme heterogeneity in the definition of the anatomic boundaries of LND templates. All seven studies comparing LND with no LND favored LND in terms of better oncologic outcomes. Seven of 14 studies comparing (super)extended LND with L-LND or S-LND reported a beneficial outcome for (super)extended LND in at least a subset of patients. No difference in outcome was reported in two studies comparing E-LND and S-LND. The comparative harms of different extents of LND remain unclear.

Conclusions: Although the quality of the data was poor, the available evidence indicates that any kind of LND is advantageous over no LND. Similarly, E-LND appears to be superior to lesser degrees of dissection, while SE-LND offered no additional benefits. It is hoped that data from ongoing randomized clinical trials will clarify remaining uncertainties.

Patient summary: The current literature suggests that removal of lymph nodes in bladder cancer surgery is beneficial and might result in better outcomes in terms of prolonging survival; however, the quality of the available studies is poor, and high-quality studies are needed.