Impact of adequate pelvic lymph node dissection on overall survival after radical cystectomy: A stratified analysis by clinical stage and receipt of neoadjuvant chemotherapy.

Purpose: An adequate pelvic lymph node dissection (LND) during radical cystectomy (RC) for muscle-invasive bladder cancer (BCa) has been shown to provide a survival benefit. We designed a study to assess the effect of adequate LND on overall survival (OS) according to cT stage and receipt of neoadjuvant chemotherapy (NAC).

Material And Methods: We identified 16,505 patients with localized BCa who received RC in the National Cancer Database (2004-2012). Inverse probability of treatment weighting (IPTW)-adjusted Kaplan-Meier and Cox regression analyses were used to compare OS between patients who received adequate LND (defined as ≥10 nodes removed) and those who did not, stratified by cT stage and receipt of NAC.

Results: Overall 8,673 (52.55%) patients underwent adequate LND at RC for localized BCa. Median time to last follow-up was 55.49 months (IQR, 34.73-75.96 months). IPTW-adjusted Kaplan-Meier curves showed that median OS was improved in patients who received adequate LND (60.06 vs. 46.88 months). In patients who did not receive NAC, adequate LND was associated with an OS benefit for cT1/a/cis, cT2, and cT3/4 disease (P ≤ 0.008). Among patients who received NAC, adequate LND was not associated with any OS difference regardless of cT stage.

Conclusion: Our data suggest that patients who did not receive NAC benefit from an adequate LND. However, the receipt of an adequate LND was not associated with an OS benefit in patients pretreated with NAC. Our study indicates that the receipt of NAC may eradicate micrometastatic disease, and thus limit the benefit of an adequate LND.