Introduction: UGN-101 has been approved for the chemoablation of low-grade upper tract urothelial cancer (UTUC) involving the renal pelvis and calyces. Herein is the first reported cohort of patients with ureteral tumors treated with UGN-101. Methods: We performed a retrospective review of patients treated with UGN-101 at 15 high volume centers and compare outcomes of those with ureteral tumors with or without renal pelvis tumors and those with only renal pelvis tumors. Efficacy endpoints were evaluated via results at first endoscopic evaluation as well as rates of recurrence and progression. Adverse outcomes were characterized with a focus on the rate of ureteral stenosis. Results: In a cohort of 132 patients and 136 renal units, 47 cases had tumor involvement of the ureter, with 12 cases of ureteral tumor only (8.8%) and 35 cases of ureteral plus renal pelvic tumors (25.7%). There was no difference in outcomes at first endoscopic evaluation between cases involving the ureter versus cases without ureteral involvement (p = 0.644). There was also no difference in recurrence rate or progression based on tumor location. Fourteen patients (37.8%) with ureteral tumor had significant ureteral stenosis at first post-treatment evaluation, however, when excluding those with pre-existing hydronephrosis or ureteral stenosis, only 5.4% of patients developed new clinically significant stenosis. Conclusions: UGN-101 appears to be equally safe and efficacious in treating low grade urothelial carcinoma of the ureter as compared to renal pelvic tumors. SOURCE OF Funding: none
