This study will, for the first time, establish a non-invasive diagnostic model for bladder cancer based on CREPT expression levels in exfoliated urothelial cells using a multicenter cohort, and validate its value in the non-invasive diagnosis and recurrence monitoring of bladder cancer. Its high sensitivity is expected to overcome the technical limitations of existing biomarkers and provide an innovative solution for establishing an integrated precision diagnosis and treatment system encompassing "screening, diagnosis, and monitoring."

The main research content of this project will be carried out from the following aspects: (1) Establish an exploratory cohort comprising patients with bladder cancer, patients with benign urological diseases, and healthy individuals. The exploratory cohort will be randomly divided into a training cohort and an internal validation cohort in a 2:1 ratio. Using the training cohort, a non-invasive detection method for bladder cancer based on CREPT expression in exfoliated urothelial cells will be developed, and a non-invasive diagnostic model for bladder cancer based on CREPT expression in exfoliated urothelial cells will be constructed. The diagnostic performance of the model will then be validated using the internal validation cohort; (2) Establish an external validation cohort including patients with bladder cancer, benign urological diseases, and healthy individuals to evaluate the clinical diagnostic performance of the model; (3) Enroll patients with bladder cancer undergoing follow-up cystoscopy after Transurethral Resection of Bladder Tumor (TURBT) and patients requiring repeat TURBT to establish a recurrence monitoring cohort, and evaluate the performance of this diagnostic model in predicting bladder cancer recurrence.

Inclusion Criteria:

• (1) Patients diagnosed with or suspected of having bladder cancer; (2) Patients with benign urological diseases, including ureteral calculi, bladder calculi, cystitis, and ureteral stricture; (3) Consent to the use of experimental urine specimens and tissue specimens; (4) Aged 18 to 75 years; (5) Willing to sign informed consent, comply with the protocol, demonstrate good adherence, and cooperate with follow-up visits.

Exclusion Criteria:

• (1) History of other malignant tumors within 5 years or prior receipt of any anti-cancer treatment; (2) Urothelial carcinoma coexisting with other genitourinary tumors (e.g., renal cell carcinoma or prostate cancer); (3) Non-standard procedures for sample collection or storage; (4) Incomplete relevant information of the subject; (5) Patients with insufficient communication, comprehension, or cooperation, or poor compliance, who cannot guarantee completion of follow-up as required; (6) Subjects deemed by the investigator to be unsuitable for participation in this clinical trial for any other reasons, leading to withdrawal from the study.

Collect urine samples from patients diagnosed with or suspected of having bladder cancer. After urine collection, detect CREPT expression in exfoliated urothelial cells using immunocytochemistry, and perform conventional urinary cytology / FISH testing.