Kidney sparing surgery in upper tract urothelial carcinoma: paradigm change in surgical treatment for ureter cancer

Purpose To extend the indications of kidney-sparing surgery (KSS) for ureter cancer by comparing the oncological outcomes between patients with upper tract urothelial carcinoma (UTUC) who underwent radical nephroureterectomy (RNU) or KSS. Methods We retrospectively reviewed 708 patients with UTUC who underwent RNU (N = 646) or KSS (N = 62) between 2011 and 2019 to analyze the oncologic outcomes and prognostic factors. Subgroup analyses were performed for patients with unifocal ureteral urothelial carcinoma (UC). Results No significant difference was observed in the overall survival (OS) or cancer-specific survival (CSS) between RNU and KSS (distal ureterectomy with reimplantation (N = 33), ureterectomy with ileal ureter (N = 14), ureteroscopic tumor resection (N = 10), and ureterectomy with ureteroureterostomy (N = 5)). Among 269 (38.0%) patients with unifocal ureteral UC, 219 and 50 patients underwent RNU and KSS, respectively. OS and CSS were not significantly different between these two groups. Pathologic stage was a significant risk factor in multivariate analysis (hazard ratio = 2.621; p = 0.000). Among 646 RNU patients, 219 (33.9%) had unifocal ureteral UC, 40 (18.3%) with low-grade tumors. Among these, 13 (5.9%) patients with unifocal, low-grade and small (