A Novel Risk-based Approach Simulating Oncological Surveillance After Radical Nephroureterectomy in Patients with Upper Tract Urothelial Carcinoma

Abstract

BackgroundThe current guideline lacks evidence for creating individualized surveillance strategies for upper tract urothelial carcinoma (UTUC) patients after radical nephroureterectomy (RNU). ObjectiveTo create a novel risk model and to simulate individualized surveillance duration that dynamically illustrates the changing risk relationship of UTUC-related death and non-UTUC death, considering the impact of cigarette smoking. Design, setting, and participantsThis multicenter cohort study comprised 714 pTa-T4N0M0 UTUC patients, with a median follow-up duration of 65mo. There were 279 (39.1%) nonsmokers, 260 (36.4%) current smokers, and 175 (24.5%) ex-smokers. InterventionAll patients underwent RNU. Outcome measurements and statistical analysisThe risks of UTUC death and non-UTUC death over time were estimated using parametric models for time to failure with Weibull distributions. Age-specific, stage-specific, and smoking status-specific surveillance durations were simulated based upon Weibull estimates. Results and limitationsThe hazard rate (HR) of non-UTUC death gradually increased over time in all age groups regardless of the smoking status, whereas that of UTUC-related death decreased markedly according to the pathological T (pT) stage and was affected by the smoking status. Among current smokers, the baseline HR of UTUC-related death in pT3/4 was higher than that of pT ≤2 and remained high even 10yr after RNU. Among heavy smokers, the HR of UTUC-related death in all pT stages was highest at baseline and remained high after RNU, compared with nonsmokers, current smokers, or ex-smokers. We simulated specific time points when the risk of non-UTUC death was greater than that of UTUC-related death. Among patients ≥80yr of with pT3N0M0, the risk of non-UTUC death was greater than that of UTUC-related death 1yr after RNU in nonsmokers, but 7yr for heavy smokers. ConclusionsOur result revealed that smokers bear a long-term risk burden of UTUC-related death more than the risk of non-UTUC death. For UTUC smokers, longer-term surveillance duration is recommended even in elderly stage. Patient summaryIn the present study, we evaluated the risk transition of upper tract urothelial carcinoma (UTUC)-related death and non-cancer-related death over time. We found that smoking weighed a huge impact upon UTUC-related death compared with death from other cause, and therefore, we created a more individualized surveillance duration model.