Future strategies to enhance kidney preservation in upper urinary tract urothelial carcinoma

Though radical nephroureterectomy remains the gold standard treatment for high grade or invasive disease in upper tract urothelial cancer (UTUC), kidney-sparing surgery has become preferred for low risk disease, in order to minimize morbidity and preserve renal function. Many methods exist for endoscopic management, whether via an antegrade percutaneous or retrograde ureteroscopic approach, including electroresection, laser ablation, and fulguration. There has been an increase in use of adjuvant intracavitary therapy, predominantly using mitomycin and bacillus Calmette-Guerin (BCG), to reduce recurrence after primary endoscopic management for noninvasive tumors, although efficacy remains questionable. Intraluminal BCG has additionally been used for primary treatment of CIS in the upper tract, with around 50% success. Newer investigations include use of narrow band imaging or photodynamic diagnosis with ureteroscopy to improve visualization during diagnosis and treatment. Genomic characterization may improve selection for kidney-sparing surgery as well as identify actionable mutations for systemic therapy. The evolution in adjuvant management has seen strategies to increase the dwell time and the urothelial contact of intraluminal agents. Lastly, chemoablation using a hydrogel for sustained effect of mitomycin is under investigation with promising early results. Continued expansion of the armamentarium available and better identification and characterization of tumors ideal for organ-sparing treatment will further improve kidney preservation in UTUC.