Background: UTUC is less common and associated with poorer stage-for-stage prognosis compared to urothelial bladder cancer. AC is regarded as a standard-of-care in high-risk UTUC based on superior disease-free survival compared to observation in the POUT trial, though fewer than 10% of patients in this trial had lymph node involvement.¹ CheckMate 274 revealed lesser magnitude of benefit with adjuvant nivolumab in UTUC compared to bladder cancer on post hoc analysis.² The preferred sequence of perioperative systemic therapy in node positive UTUC remains unclear. Methods: We queried the National Cancer Database for adult patients with clinically node positive (cTanyN1-3M0) UTUC diagnosed between 2004 and 2018. Patients were divided into two groups based on the perioperative treatment strategy - NAC or AC. Patients who did not undergo RNU were excluded from analyses. Fisher’s exact and Mann Whiney U tests were used to compare frequency distributions. Cox Proportional Hazards regression was employed for multivariate analysis of factors associated with overall survival. Models were adjusted for age, sex, race, income, educational level, clinical T stage, insurance status, and the Charlson Comorbidity Index. Results: A total of 862 patients were identified - 362 (42%) underwent NAC while 500 (58%) received AC. No significant differences were noted between the groups regarding age, sex, or insurance status. Patients with cT1-2 UTUC more often received NAC (27.9% vs 11.8%, P <0.001) while those with cT3-4 disease more frequently received AC (38.9% vs 57.4%, p<0.001). Rates of NAC vs AC were not significantly different based on clinical N stage (P = 0.35). Overall survival in the NAC group was significantly longer than the AC group (median of 47.1 vs. 20.2 months, log-rank P < 0.001). On multivariable analysis, only the sequence of perioperative chemotherapy was independently predictive of overall survival (Hazard Ratio of 1.38 for AC, with 95% CI 1.14-1.68, P = 0.001). Conclusions: In this large retrospective analysis of outcomes among patients with clinically node positive UTUC who underwent RNU, NAC was associated with significantly longer overall survival compared to AC. References: 1) Birtle A, Lancet 2020; 2) Bajorin DF, NEJM 2021.