Circulating Tumor DNA in Bladder Cancer: Current Clinical Evidence and Emerging Multi-Omics Perspectives—A Narrative Review
Simple Summary Muscle-invasive bladder cancer is an aggressive disease in which many patients remain at risk of recurrence despite surgery and standard treatments. There is an urgent need for better tools to identify patients who may benefit from additional therapies or, conversely, avoid unnecessary treatment-related toxicity. Circulating tumor DNA, a small amount of tumor-derived genetic material detectable in blood, has emerged as a promising marker for monitoring residual disease and predicting treatment response. In this review, we summarize the current evidence on the clinical applications of circulating tumor DNA in muscle-invasive bladder cancer, including its role in prognosis, treatment selection, and surveillance. We also discuss future perspectives for integrating molecular monitoring into personalized cancer care.