A Study Comparing the Necessity of a Second Transurethral Resection in High-Risk Non-Muscle-Invasive Bladder Cancer Patients With Negative Results From Post-Initial Resection Urine Genome-Wide Low-Depth Sequencing

Inclusion Criteria: * Patients with NMIBC who have completed the initial transurethral resection and are scheduled for a second resection, as recommended by guidelines or physician's choice: 1. Incomplete initial TURBT due to various reasons (including large tumor size, high risk of intraoperative bleeding, extensive tumor range, etc.), posing a risk of residual tumor; 2. Absence of muscle layer tissue in the initial resection specimen; 3. Post-initial resection pathology indicating T1 stage; 4. Post-initial resection pathology indicating G3/high-grade tumor, excluding pure carcinoma in situ; * Ability to provide a 100ml routine urine sample within 1-6 weeks after the initial resection and before the second resection; * Age ≥ 18 years; * Willingness to provide basic clinical information, pathology, and subsequent - recurrence monitoring results; * Willingness to sign the informed consent form. Exclusion Criteria: * Patients with other non-urothelial malignant tumors (including prostate cancer and renal cell carcinoma); * Patients previously diagnosed with muscle-invasive bladder cancer; * Patients unable to undergo a second resection; * Patients with incomplete pathological information of the sample; * Patients with contaminated samples; * Patients whose urine samples fail quality control for valid reasons and cannot be resampled; * Any condition deemed by the investigator as potentially harming the subject or preventing the subject from meeting or fulfilling the study requirements; * Patients unable to provide written informed consent.