The Influence of Lymph Node Count on Oncological Outcome of Radical Cystectomy in Chemotherapy Pre-Treated and Chemotherapy-Naïve Patients with Muscle Invasive Bladder Cancer

Radical cystectomy (RC) with pelvic lymph node dissection (PLND) remains the mainstay of treatment for muscle-invasive bladder cancer (MIBC). The extent of PLND and number of removed lymph nodes (LNs) have been associated with improved staging and survival outcomes in several series of RC patients. Neoadjuvant chemotherapy (NAC) has become standard of care for cisplatin-eligible patients qualified to RC, yet few studies on PLND stratified cases according to the receipt of NAC. We aimed to address this issue and reevaluate the prognostic value of PLND nodal yields in series of patients who underwent RC on the verge of the NAC era. This single-center, retrospective, clinical follow-up study enrolled 439 consecutive patients, out of whom 83 received NAC. We analyzed survival outcome of RC according to the number of removed nodes between NAC and non-NAC subgroups. We found PLND thresholds of 10 and 15 LNs prognostically meaningful in our study cohort, and this association was particularly pronounced in the non-NAC subgroup. Higher numbers of LNs provided a 25% reduction in risk of all-cause mortality and correspondingly correlated with up to a 14% increase in 3-year overall survival. The receipt of NAC diminished the benefit of adequate PLND, as the number of retrieved LNs was not associated with survival in the NAC-RC cohort. Given the limitations of our study, additional research is needed to verify these findings.