<![CDATA[High-risk upper tract urothelial carcinoma (UTUC) is an aggressive disease for which radical nephroureterectomy (RNU) remains the standard treatment but is associated with significant postoperative renal function decline. Kidney-sparing surgery (KSS) has emerged as a potential alternative in carefully selected patients to preserve renal function while maintaining oncological control. However, evidence regarding long-term oncological and functional outcomes of KSS in high-risk UTUC remains limited and heterogeneous, and optimal patient selection criteria are not well defined. Therefore, this systematic review aims to evaluate the available evidence to clarify the role of KSS in this clinical setting. We conducted a PRISMA 2020-compliant systematic review of observational studies comparing KSS (segmental ureterectomy or endoscopic/percutaneous management) with RNU in adults with high-risk UTUC, defined by ≥pT2 stage, high-grade histology, tumor size ≥2 cm, multifocality, hydronephrosis, or variant histology. PubMed, Scopus, and Embase were searched. Survival outcomes, recurrence patterns, renal function, and complications were extracted. Due to study heterogeneity, results were synthesized narratively. Four retrospective comparative studies, including approximately 700 patients, were identified. Five-year cancer-specific and overall survival were comparable between KSS and RNU, ranging from approximately 70% to 86%. Ipsilateral upper-tract recurrence was higher following KSS, particularly after endoscopic management, while rates of distant metastasis and bladder recurrence were similar. Distal ureterectomy achieved oncologic outcomes comparable to RNU for distal ureter tumors, whereas renal pelvis or proximal ureter tumors had higher recurrence. KSS consistently preserved renal function better. Overall, KSS appears safe and effective for carefully selected patients with small, unifocal distal ureter tumors or imperative indications for nephron preservation. Caution is warranted for large, multifocal, or renal pelvic/proximal ureter tumors. Prospective studies and biomarker‑based risk stratification are needed to refine patient selection.Keywords: Upper Tract Urothelial Carcinoma, Kidney-Sparing Surgery, Radical Nephroureterectomy, Survival, Renal Function.]]>
