Endoscopic excision versus radical nephroureterectomy for non-muscle invasive upper tract urothelial carcinoma: A population-based large cohort study

Background: As an important kidney-sparing treatment for upper urothelial carcinoma (UTUC), whether endoscopic excision can be performed without sacrificing oncologic outcomes remains indefinite. This study aimed to investigate the prevalence and efficacy of endoscopic excision, in patients with non-muscle invasive UTUC (NMIUTUC) and compare them to those of radical nephroureterectomy (RNU).Methods: Using the Surveillance, Epidemiology, and End Results database, we reviewed 4347 cases with NMIUTUC (cTis/Ta/T1-N0-M0,<= 5.0 cm) between 2004 and 2020. Surgical treatment modalities included endoscopic excision and RNU. Propensity score matching analysis was used to minimize the selection bias between endoscopic excision and RNU, selecting 1:1 matched patients in the two group.Results: A total of 794 patients with NMIUTUC were included after matching (397:397). Patients who underwent endoscopic excision had worse survival outcomes compared with those of pa-tients who underwent RNU (5-year OS: 65.3 % vs. 80.3 %, p < 0.0001; 5-year DSS: 83.2 % vs. 94.0 %, p = 0.00021). After stratification by anatomical sites, the effect of endoscopic excision for NMI renal pelvis cancer was worse than RNU (5-year OS, 62.9 % vs. 82.8 %; 5-year DSS, 78.8 % vs. 91.6 %), while in NMI ureteral cancer, there is no statistically significant difference in OS and DSS between endoscopic excision and RNU. Further stratification according to tumor grade revealed equivalent tumor control effects of endoscopic excision and RNU in low-grade NMI ureteral cancer (5-year OS: 67.7 % vs. 72.5 %, p = 0.23; 5-year DSS: 87.2 % vs. 93.1 %, p = 0.17); while for renal pelvis tumor and high-grade ureteral tumor, endoscopic excision was related with significantly inferior prognosis.Conclusions: Only for low-grade NMI ureteral cancer, endoscopic excision and RNU are onco-logically equivalent, indicating that endoscopic excision might be an effective option for low-grade NMI ureteral cancer. This result needs to be further verified in randomized controlled trials.