Introduction:

Utility of lymph node dissection (LND) in localized upper tract urothelial carcinoma (UTUC) is controversial. In this analysis, we evaluated the impact of LND on prognosis, survival, and oncologic outcomes in patients with UTUC using a multi-institutional dataset. 

Methods:

We performed a retrospective analysis utilizing the ROBUUST (RObotic surgery for Upper Tract Urothelial Cancer Study) registry of UTUC patients undergoing nephroureterectomy from 2006-2019. The cohort was divided into patients who did not undergo LND (pNx), patients who underwent LND with negative lymph nodes (pN0), and patients who underwent LND with positive nodes (pN+). Primary and secondary outcomes were overall survival (OS) and progression-free survival (PFS). Multivariable analyses (MVA) were conducted for predictors of outcomes and pathologic node positivity. Kaplan-Meier analyses (KMA) were utilized to compare survival outcomes between pNx, pN0, and pN+ groups and to evaluate outcomes based on number of nodes removed.

Results:

877 patients were analyzed [LND performed in 358 (40.8%)/pN+ in 73 (8.3%)]. Median nodes obtained were 10.2 for pN+ and 9.8 for pN0. MVA noted increasing age (OR 1.1, p<0.001), pN+ (OR 3.1, p<0.001), and pathologic stage pTis/3/4 (OR 3.4, p<0.001) as predictors for all-cause mortality. MVA noted increasing age (OR 1.01 , p=0.031), and pN+ (OR 1.7, p=0.007) to be predictive for recurrence. Clinical high-grade (OR 12.14, p=0.014) and Tumor Size ≥4.5 cm (OR 2.12, p=0.005) were predictive for lymph node positivity on LND. KMA for pNx, pN0 and pN+ groups demonstrated: 5-year OS of 77%, 77%, and 44% (p<0.001) and 5-year PFS of 45%, 59%, and 26% (p<0.001). KMA comparing pNx, pN0≥10 nodes, and pN0<10 nodes showed no significant different in 5-year OS (70% vs. 83% vs. 70%, p=0.854) but elicited significantly higher 5-year PFS in the pN0≥10 node group (73% vs. 47%, vs. 39%, p=0.044).

Conclusion:

In the present multi-national cohort of patients undergoing minimally invasive nephroureterectomy, performance of LND provides important prognostic data, but is not associated with improved OS. In patients with high grade disease and tumor size ≥4.5cm, lymphadenectomy should be considered. Furthermore, lymph node yield ≥10 in patients with pN0 disease may be associated with improved recurrence free survival. Taken together, our data point to refinement of selection criteria and outcomes for lymphadenectomy in nephroureterectomy patients.

Funding: Stephen Weissman Kidney Cancer Fund