Update of the Diagnostic and Therapeutic Role of the Pelvic Lymph Node Dissection Boundaries During Radical Cystectomy in Muscle Invasive Bladder Cancer

Radical cystectomy (RC) is the gold standard treatment option for muscle invasive bladder cancer (MIBC). However, up to 25% of patients who undergo RC show metastatic lymph node deposits during the procedure. In such cases, the 5-year survival rate is reported to be 25%–30%. Pelvic lymph node dissection (PLND) can also provide useful prognostic information, including data regarding the disease burden, lymph node density, and extracapsular extension of metastatic lymph nodes. Accordingly, the National Comprehensive Cancer Network guidelines recommend that PLND that includes the common iliac lymph node should be performed at the time of RC to allow reliable staging of MIBC. In addition to its diagnostic role, many studies have reported the potential therapeutic role of PLND. Data from clinical trials indicate a substantial oncological advantage in PLND cohorts compared to non-PLND cohorts, regardless of pathological nodal status, as a result of removal of metastatic and micrometastatic tumor cells nested in lymph nodes. As such, despite the diagnostic and therapeutic role of PLND in MIBC, the optimal PLND template remains controversial. Currently, extended PLND (E-PLND) is recommended for diagnostic purposes, however, E-PLND did not show therapeutic effectiveness in some recent preliminary randomized controlled trials. In this review, we will discuss the appropriate range of PLND for RC in terms of its diagnostic and therapeutic importance, and propose an appropriate range of PLNDs based on the evidence and randomized trials so far.