ASCO GU 2022: Survival Outcomes Comparing Radical Nephroureterectomy Versus Endoscopic Treatment in Solitary Kidney Patients Diagnosed With Upper Tract Urothelial Carcinoma

(UroToday.com) When curative treatment of a cancer comes at the expense of critical organ and organ function, the patient and doctor are faced with a daunting challenge. Once such scenario highlighted by Dr. Alam is development of upper tract urothelial carcinoma (UTUC) in a person with a solitary kidney. Radical nephroureterectomy (RNU) may be curative but will render the patient dialysis-dependent, with the associated reduced quality and length of life dialysis brings. An alternative is organ-sparing endoscopic treatment which may spare the remaining kidney but be less effective, representing suboptimal cancer treatment. As presented in their poster, the authors compared survival outcomes between RNU and endoscopy in solitary kidney patients diagnosed with clinically localized UTUC to determine differences in overall outcome.

To answer their question, patients with UTUC through the year 2017 were identified from the Surveillance, Epidemiology, and End Results (SEER) crossed against Medicare provider and claims data to identify patients with solitary kidney. Analysis was limited to patients with solitary kidney antecedent to localized UTUC (cN0M0). After stratification for treatment (RNU v endoscopy), Kaplan-Meier methodology was performed to estimate survival in each group.

2108 patients were identified who met the aforementioned study criteria. Median age at diagnosis was 75.3 years (IQR 69.3-81.1) and with a median follow up time of 2.8 years (IQR 1.7-4.4). Vital statistics were similar across the two groups, both in full cohort and only those with high grade disease.

The authors tested for associations using Cox regressions to evaluate other contributors to overall survival, identifying antecedent ESRD and high grade UTUC as highly significant risk variables.

In the analysis ooverall survival, no difference was observed between two treatment modalities in the entire cohort (not show) or in the high grade group (5 year OS: RNU 41.7% v endoscopic 39.2%, p=0.10). Cancer-specific mortality was also not different at 5 years (25.1% v 16/1%, p=0.08. In contrast, non-cancer specific mortality was higher in the endoscopic group (53.3% v 44.2%, p=0.008), a comparison with a smaller effect size but greater power to detect a difference, it appears.

Perhaps as a surprise, no difference in survival outcomes was observed when comparing RNU to endoscopic treatment of UTUC in patients with a solitary kidney. Yet, prognosis remains poor, with <50% 5 year survival in treated patients with UTUC in their solitary kidney. These data do not incorporate quality of life, which could be different if cancer-directed therapies were needed or in the face of hemodialysis, but suggest promising survival equivalency with which to council patients in this unfortunate situation.