A multi-institutional study published in European Urology introduces a novel urine-based tumor DNA assay to predict recurrence risk in bladder cancer patients undergoing atezolizumab immunotherapy. This biomarker quantification provides non-invasive monitoring of non–muscle-invasive bladder cancer, notably among patients unresponsive to Bacillus Calmette-Guérin treatment. The research leverages data from the SWOG S1605 trial and represents a significant step toward personalized management of this prevalent malignancy by enabling risk stratification and improved therapeutic decision-making.