This study looks at a type of cancer called Upper Tract Urothelial Carcinoma (UTUC), which affects the urinary system. The goal is to see how patients do after a treatment that tries to save their kidneys. Normally, a surgery called nephroureterectomy is done to remove the kidney and ureter in high-risk cases, but it can hurt kidney function. A newer option, kidney-sparing surgery, might help some patients keep their kidneys without affecting their chances of survival. This study checks how well this new approach works in real life.

• The study is for adults aged 18-90, with cancer confirmed by a doctor.
• Participants must agree to follow-up visits and sign consent forms.
• People who can't have the kidney-sparing surgery or have less than 6 months to live cannot join.