Contemporary conditional cancer-specific survival after radical nephroureterectomy in patients with nonmetastatic urothelial carcinoma of upper urinary tract

Background and Objectives: To examine the effect of conditional survival on 5-year cancer-specific survival (CSS) probability after radical nephroureterectomy (RNU) in a contemporary cohort of patients with non-metastatic urothelial carcinoma of the upper urinary tract (UTUC). Methods: Within the Surveillance, Epidemiology and End Results database (2004-2015), 6826 patients were identified. Conditional 5-year CSS estimates were assessed after event-free follow-up duration. Multivariable Cox regression (MCR) models predicted cancer-specific mortality (CSM) according to event-free follow-up length. Results: Overall, 956 (14.0%) were T₁low grade(LG)N₀, 1305 (19.1%) T₁high grade(HG)N₀, 1215 (17.8%) T₂N₀, 2249 (32.9%) T₃N₀ and 1101 (16.1%) T₄N₀/T_anyN_1-3. From baseline, 93.4% to 94.2% in T₁LGN₀ provided 5-year CSS and, respectively, 86.2% to 95.3% in T₁HGN₀, 77.5% to 87.8% in T₂N₀, 63.0% to 91.1% in T₃N₀, and 38.8% to 88.2% in T₄N₀/T_anyN_1-3. In MCR models, relative to T₁LGN₀, T₁HGN₀ (Hazard ratio [HR] 1.7), T₂N₀ (HR 3.0), T₃N₀ (HR: 5.2), and T₄N₀/T_anyN_1-3 (HR 11.9) were independent predictors of higher CSM. Conditional HRs decreased to levels equivalent to T₁LGN₀ at 3 years vs 5 years of event-free survival for T₁HGN₀ and all other groups, respectively. Conclusions: A direct relationship exists between event-free follow-up and survival probability after RNU. From a clinical perspective, such survival estimates may have particular importance during preoperative counseling.