Presentation Authors: Shigeta Keisuke*, Eiji Kikuchi, Masayuki Hagiwara, Takayuki Abe, Koichiro Ogihara, Ryuichi Mizuno, Mototsugu Oya, Tokyo, Japan
Introduction: 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.
Methods: 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.
Results: The figure shows the risk transition of UTUC related death and non-UTUC death of heavy smokers (number of cigarette packs a day x number of years â‰¥50) after RNU. The Weibull model indicates that the risk hazard of UTUC-related death showed a higher amount in patients with advanced stage (e.g. pT4 patients had a 3.5 times higher hazard rate (HR) of UTUC-related death than â‰¤pT1 at baseline). While the risk of â‰¤pT1 and pT2 gradually decreased as survival period increased from RNU, the risk of UTUC-related death elevation of pT3 and pT4 remained high even ten years after RNU (e.g. the HR of pT4 patients was 3.4 times higher than â‰¤ pT1 at 10 years after RNU). In contrast, the HR of non-UTUC death showed a higher amount in the elderly stage but only a gradual increase was observed in all age groups. In nonsmokers, the HR of pT4 patients was 0.75 times higher than pT4 heavy smokers at baseline, and HR drastically declined to 0.22 ten years after RNU compared to heavy smokers. Moreover, more than 10 years smoking cessation lowered the HR of UTUC-related death in â‰¤pT1 and pT2 patients, while it remained high in pT3 and pT4 patients. 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 â‰¤pT1, at 2 years for pT2, at 7 years for pT3, and at 9 years for pT4.
Conclusions: 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.