Relationship between the number of lymph nodes dissected and prognosis in muscle‐invasive bladder cancer in the era of neoadjuvant chemotherapy

Abstract

Objectives Many studies have shown a good prognostic association with a large number of lymph node dissections. However, most of these studies did not include patients who have received neoadjuvant chemotherapy. The purpose of this study was to verify the relationship between survival outcomes and the number of lymph nodes removed during radical cystectomy in patients with muscle‐invasive bladder cancer in the era of neoadjuvant chemotherapy. Methods This retrospective study considered patients who were diagnosed with clinical ≥T2N0M0 muscle‐invasive bladder cancer and treated with radical cystectomy at the Nagoya University Hospital and affiliated hospitals from January 2004 to December 2019. We excluded patients who had a history of upper tract urothelial cancer or non‐urothelial carcinoma. The association between prognosis and the number of lymph nodes removed was investigated. Results We retrospectively enrolled a total of 477 patients. The mean number of lymph nodes dissected was 14. Two hundred and twenty‐six patients (47.4%) received neoadjuvant chemotherapy. More extensive lymphadenectomy (≥15 lymph nodes) correlated with better 5‐year overall survival across all patients (68% vs. 57%, p = 0.01). In patients who received neoadjuvant chemotherapy, there was no difference in overall survival according to the number of dissected lymph nodes (66% vs. 71%, p = 0.433). In patients who did not receive neoadjuvant chemotherapy, ≥15 lymph nodes dissected was associated with significantly better overall survival (70.3% vs. 46.9%, p < 0.01). Conclusions No association between more aggressive lymph node dissection and prognosis was found in patients who underwent neoadjuvant chemotherapy. Conversely, extended lymph node dissection is desirable for patients who have not received neoadjuvant chemotherapy.

Adequate Pelvic Lymph Node Dissection in Radical Cystectomy in the Era of Neoadjuvant Chemotherapy: A Meta-Analysis and Systematic Review

“…Hence, new drugs are increasingly introduced as a salvage approach, with immune checkpoint inhibitors appearing most promising in this setting [ 27 ]. The role of NAC in treating micrometastases and preventing distal metastases after RC is analogous to the therapeutic significance of PLND [ 10 ]. In our meta-analysis, patients exposed to NAC no longer obtained an oncological benefit from more extensive lymphadenectomy.…”

“…Two studies included in this meta-analysis provided data on the chemotherapy regimens used. In the studies from Poland and Japan, the dominant regimens were ddMVAC and GC, respectively [ 9 , 10 ]. Despite a higher rate of extravesical disease in the Polish study, both reported similar pPR and pCR rates.…”

“…Additionally, in both studies, adequate PLND did not improve survival in the NAC pre-treated patients. However, the Japanese study only analyzed one out of two thresholds of PLND [ 10 ]. To date, no study has assessed the importance of adequate PLND in relation to a specific NAC regimen.…”

“…The following search keywords were utilized: (overall survival OR survival OR prognosis) AND (radical cystectomy) AND (neoadjuvant chemotherapy) AND (pelvic lymph node dissection OR lymph node counts OR lymphadenectomy). Moreover, the references in the included studies, along with those of a previous systematic review, were examined [ 9 , 10 , 11 , 12 ]. All the studies included in this analysis were published in English.…”

Lymph node ratio is a prognostic indicator for locally advanced esophageal squamous cell carcinoma after neoadjuvant immunochemotherapy

“…Therefore, the accuracy of the ypN stage might be seriously compromised due to the insufficient number of TLNs [ 13 ]. Moreover, several published studies have also shown a positive association between a higher number of TLNs and better prognosis [ 14 , 15 ]. Therefore, evaluating both the number of TLNs and PLNs is important in cancer treatment.…”