Nephron-sparing approaches in the management of upper tract urothelial carcinoma: indications and clinical outcomes.

Given the more aggressive phenotype and prognosis of the upper tract urothelial carcinoma (UTUC) than those of bladder tumor, radical removal of the entire ureter along with ipsilateral kidney has long been the standard of care. However, recent advances in diagnostic imaging and endoscopic armamentarium have markedly enhanced the role of nephron-sparing approaches for well-selected cases, especially with low-risk features. Historically, this strategy was exclusively considered for managing a patient unfit to undergo radical nephroureterectomy (RNU). After observing effective oncologic control for these imperative cases, an elective risk-based indication was introduced with care. Two representative modalities in this strategy include endoscopic management via retrograde ureterorenoscopy (URS) or antegrade percutaneous approach and segmental ureterectomy (SU). SU, which includes different types of unstandardized procedures, is the most widely reported alternative to RNU. Despite the lack of qualified evidence regardless of the strategy applied, systemic reviews have consistently revealed similar survival after endoscopic management and RNU for low-grade and noninvasive UTUC. However, selected patients with high-grade and invasive UTUC could benefit from SU while maintaining the oncologic outcomes observed after RNU. Based on these findings, the currently available guidelines have extended the use of the nephron-sparing approach gradually, recommending segmental resection especially for the distal ureteral tumors even in patients with high-risk features. Nonetheless, the fact that evidence supporting these conclusions remains poor and potentially biased cannot be overemphasized.