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/TanyN1-3. 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/TanyN1-3. In MCR models, relative to T1LGN0, T1HGN0 (Hazard ratio [HR] 1.7), T2N0 (HR 3.0), T3N0 (HR: 5.2), and T4N0/TanyN1-3 (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.