Since smoking has a causal relationship not just with oncological outcomes but also with aggravating the general health conditions of upper tract urothelial carcinoma (UTUC) survivors, our specific aim is to introduce an individualized risk-based surveillance regimen which interacts with smoking status.
We identified 714 non-metastatic UTUC patients who underwent radical nephroureterectomy (RNU). The patients were stratified by pathologic stage, chronological age, and smoking status. The risks of UTUC death and non-UTUC death were estimated by using parametric models for time-to failure with Weibull distributions.
The hazard rate (HR) of non-UTUC death overtime gradually increased in all age groups regardless of the smoking status, whereas that of UTUC-related death markedly decreased according to the 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 ten years after RNU. Among heavy smokers, the HR of UTUC-related death in all pT stages increased at baseline, and maintained the risks even the survival period increased after RNU. We simulated specific time points when the risk of non-UTUC death was greater than that of UTUC-related death. We further simulated age-specific, stage-specific, and smoking status specific time points when the risk of non-UTUC death exceeds the risk of UTUC-related death. Specifically, among heavy smoker patients aged >80, non-UTUC related death risk exceeded the risk of UTUC related death at 1 year after RNU for ≤pT1, at 2 years for pT2, at 7 years for pT3, and at 9 years for pT4.
The Weibull model revealed that accumulative smoking exposure would strongly affect over time the risk elevation and prolongation of UTUC related death more than elevating over time the risk of non-UTUC death. Therefore, for UTUC heavy smokers with advanced pT stages, more than 5 years of surveillance duration is recommended, even for patients who are over 80 years old.
The authors.
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All authors have declared no conflicts of interest.