Bladder cancer continues to cause significant mortality in the US due to the lack of reliable methods to identify high-risk patients who benefit from chemotherapy. We propose a study to characterize cell-free circulating DNA in the plasma for the purpose of creating a new noninvasive biomarker to identify patients with high-risk of recurrence. First, we will perform whole genome bisulfite sequencing to compare the methylation signatures between the patients who developed recurrence and those who did not. The identified differential methylation loci will be refined and then validated in a separate group of patients.