Transurethral resection of bladder tumor (TURBT) is the standard therapeutic approach for patients with non-muscle-invasive bladder cancer (NMIBC). Postoperative intravesical chemotherapy or BCG immunotherapy is commonly administered to prevent recurrence. However, limitations such as suboptimal specimen integrity and tissue artifacts from intraoperative cauterization may lead to inaccurate risk stratification in cases classified as low-risk NMIBC, complicating individualized prognostic assessment. Consequently, clinicians often resort to prolonged intravesical therapy to mitigate recurrence risk, resulting in substantial overtreatment.

Previous studies in bladder cancer have demonstrated that detection of SIX6 gene methylation in urine enables noninvasive and accurate auxiliary diagnosis, with a sensitivity of 88.9%, specificity of 94.7%, and overall accuracy of 92.9%. In this retrospective case-control study, we aim to evaluate the utility of SIX6 methylation as an objective biomarker for predicting recurrence in patients with low-risk NMIBC.

Inclusion Criteria:

1. age higher than 18;
2. patients diagnosis with non muscle invisive bladder cancer;
3. willing to provide 100Ml urine before treatment;
4. patients were diagnosis with bladder cancer for the first time

Exclusion Criteria:

1. patiens have more than one tumors besides bladder cancer;
2. pregnant women;
3. unwilling to partipate the research -

This is a biomarker-based diagnostic study where participant grouping is determined by objective laboratory testing (SIX6 methylation status). Blinding of participants or investigators is not feasible due to the nature of the diagnostic assay.