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

• 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.