Endoscopic kidney-sparing surgery for upper tract urothelial carcinoma in patients with a solitary kidney.

Abstract

To evaluate cancer control, renal function trajectories, and dialysis risk in patients with a solitary kidney treated with endoscopic kidney-sparing surgery (eKSS) for upper tract urothelial carcinoma (UTUC). We conducted a retrospective multicentre cohort study including 62 consecutive patients with UTUC and a solitary kidney treated with primary eKSS between 2006 and 2024 at two tertiary referral centres. All patients underwent ureteroscopic biopsy and laser ablation followed by intensified surveillance with mandatory second-look ureteroscopy and repeat retreatment as needed. Primary endpoints were upper tract recurrence, progression, cancer-specific mortality, and dialysis dependency. Competing-risk cumulative incidence functions and linear mixed-effects models were used. Median age was 71 years (interquartile range [IQR] 67-77), and baseline estimated glomerular filtration rate (eGFR) was 48 mL/min/1.73 m² (IQR 40-70). High-grade disease at initial ureteroscopy was present in 12 patients (19%). Over a median follow-up of 65 months, patients underwent a median of five ureteroscopies (IQR 3-9), and 16 (26%) ultimately underwent radical nephroureterectomy. The cumulative incidence of upper tract recurrence was 70% (95% confidence interval [CI] 58-83) at 5 years. The 5-year cumulative incidence of progression was 40% (95% CI 26-54). Cancer-specific mortality was 20% (95% CI 7.9-32) at 5 years. Dialysis dependency occurred in 32% (95% CI 18-45) at 5 years, predominantly among patients with baseline eGFR <30 mL/min/1.73 m² (hazard ratio 5.68; 95% CI 1.20-27.0, P = 0.029). Mixed-effects modelling showed a mean annual eGFR decline of 2.9 mL/min/1.73 m² (95% CI 1.2-4.6). In patients with UTUC and a solitary kidney, eKSS delivered within an intensive surveillance programme provided durable renal preservation with acceptable oncological outcomes. Despite frequent recurrences requiring repeated ureteroscopic interventions, cancer-specific mortality remained limited, supporting eKSS as a viable alternative to radical nephroureterectomy in imperative clinical settings.