Radiotherapy Combined with Systemic Therapy Versus Systemic Therapy for Oligometastatic UTUCs

Inclusion Criteria:

• Patients with metastatic uroepithelial cancer with histologically confirmeddiagnosis (pathologically confirmed primary focus or one of the metastatic foci issufficient) (metastasis after total cystectomy, metastasis after full-lengthnephroureteral resection, or metastatic uroepithelial cancer of the pelvic-ureteralbladder at the first diagnosis of inoperable metastatic uroepithelial cancer).

• Oligometastases were defined as ≤3 organs, and the number and size of metastaticlesions were not restricted to the extent that full-coverage radiotherapy could bemet. If regional lymph node recurrence was present, all positive regional lymphnodes were collectively referred to as one lesion. Non-regional lymph nodemetastases are counted as metastases by lymph node subregion.

• Willing and able to provide written informed consent/assent for the trial; age ≥18years on the date of signing the informed consent form and patient age ≤80 years.

• Expected survival time ≥ 6 months;

• Eastern Collaborative Oncology Group (ECOG) Physical Status (PS) score of 0 to 1;

• Normal major organ function, i.e., the following criteria are met: routine bloodtests: a) Haemoglobin ≥ 90 g/L; b) Total bilirubin ≤ 2 x upper limit of normal (ULN); c) Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkalinephosphatase (ALP) ≤ 2.5 x ULN in the absence of liver metastases, and ALT, AST andALP ≤ 5 x ULN in the presence of liver metastases; d) Creatinine clearance (CrCl) ≥30 mL/min;

Exclusion Criteria:

• Pathological type non-urothelial carcinoma;

• Patients with brain metastases and >3 liver metastases; patients with spinal bonemetastases at risk of spinal cord compression; patients with pericardial, pleural orabdominopelvic fluid;

• Patients who are intolerant to or have had a reduction in systemic therapy; patientswith tumour progression assessed after 2 cycles of systemic therapy.