Editorial Comment on “Current Kidney‐Preserving Strategies for Upper Tract Urothelial Carcinoma”

The review by Prof. Inamoto et al. summarizes kidney-preserving approaches for upper tract urothelial carcinoma (UTUC), with a main focus on laser ablation, and includes up-to-date information by concisely outlining recent advances in kidney-sparing approaches for UTUC [1]. In Japan, radical nephroureterectomy (RNU) is the primary therapeutic approach for UTUC in many institutions, regardless of the risk classification of UTUC, even in low-risk patients. As discussed in the review, limited access to laser technology or endoscopy is one of the reasons for RNU, although other factors may also play a primary role. For example, the oncological outcomes between endoscopic management and RNU for low-risk UTUC might not be considered comparable by Japanese urologists (many urologists may still consider RNU is better than endoscopic management in terms of cancer control). Additionally, clear guidelines are lacking for the selection of patients, selection of lasers (holmium: YAG vs. thulium fiber laser), and follow-up methods [1]. In 2025, updated from 2024, the EAU guidelines added two following recommendations for the kidney-sparing management of patients with low-risk UTUC: "discussing both endoscopic management and distal ureterectomy in low-risk tumors of the distal ureter based on tumor characteristics and shared decision-making with the patients" with a strong recommendation, and "performing second-look ureteroscopy within 8 weeks following initial endoscopic management" with a weak recommendation [2]. Furthermore, "offering kidney-sparing management as primary treatment option to patients with low-risk tumors" is still strongly recommended by the guidelines [2]. These recommendations clearly indicate a strong trend for kidney-sparing management of patients with low-risk UTUC. However, the recommendations for follow-up of the upper tract are relatively obscure, stating that "after negative second-look URS, perform cross-sectional imaging urography at 3 and 6 months, and then yearly for 5 years, with or without URS." These recommendations illustrate the need for more evidence to establish follow-up guidelines after kidney-sparing surgery. "The gold standard treatment for treating localized UTUC is RNU, regardless of risk"—this knowledge would be outdated in the current era of advanced imaging technologies, endoscopy, and laser. Although the possibility of upper urinary tract recurrence and repeated ureteroscopy are drawbacks of kidney-sparing management, patients with low-risk UTUC should be managed with a kidney-sparing approach, with the aim not to compromise renal function and to achieve longer life expectancy with better renal function and cancer control [3]. Although the guidelines recommend kidney-sparing management for low-risk UTUC, the current evidence is based on relatively small, retrospective cohort studies, likely due to the rarity of this disease [4]. Accumulation of clinical data based on multicenter prospective studies will be useful for the development of detailed guidelines for kidney-sparing management. Y.G. prepared the manuscript. The author has nothing to report. The author has nothing to report. The author has nothing to report. The author declares no conflicts of interest.