Radical nephroureterectomy vs kidney sparing surgery for upper tract urothelial carcinoma in solitary kidney patients: a multi-institutional analysis of the ROBUUST 2.0 registry

Purpose: Radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC) in solitary kidney patients is a rare and underreported scenario. This study aims to compare the outcomes of UTUC solitary kidney patients becoming anephric after RNU to those of patients undergoing kidney-sparing surgery (KSS). Methods: Data from patients with a solitary kidney were retrieved from the ROBUUST 2.0 database, a global, multicenter registry containing data on patients who underwent curative surgery for UTUC. Baseline patient demographics, disease characteristics, and surgical features were compared between RNU and KSS. Kaplan-Meier methods were used to estimate recurrence-free survival (RFS), metastasis-free survival (MFS), cancer-specific survival (CSS), and overall survival (OS) in patients undergoing RNU, with 3-year and 5-year cutoffs applied. Results: Thirty-nine patients (76.5%) underwent RNU, whereas 12 (23.5%) underwent KSS. Despite a comparable preoperative renal function, the distribution of CKD stages differed significantly between the groups (p = 0.019). Despite a similar rate of postoperative complications, patients undergoing RNU experienced a significantly higher median LOS (p < 0.001). Among RNU patients, OS was 83.9%, CSS was 96.9%, RFS was 71.8%, and MFS was 84.4% at the 3-year follow-up. After 5 years post-surgery, OS was 73.4%, CSS was 83.1%, RFS was 59.9%, and MFS was 78.5% in the same cohort. Conclusions: UTUC solitary kidney patients undergoing RNU or KSS face a substantial perioperative burden. Despite these challenges, our cohort demonstrated favorable oncological outcomes comparable to those reported in the existing literature.