Analyzing the Urine During BCG Instillation in Bladder Cancer Patients for Disease Followup

Bacillus Calmette-Guerin (BCG) has been extensively utilized in intravesical instillation therapy for patients with medium to high risk non-muscle invasive bladder cancer (NMIBC) following transurethral resection of bladder tumor (TURBT). Nevertheless, the efficacy of BCG instillation can fluctuate between patients, with 40.5% experiencing disease recurrence during BCG therapy. The effectiveness of BCG instillation may be linked to the urinary microbiome and immune microenvironment. Additionally, small residual lesions post-TURBT could also result in bladder cancer recurrence. Low coverage whole genome sequencing (LC-WGS) can be used to detect the urinary microbiome and chromosomal instability (CIN), making it feasible to predict the recurrence or progression of bladder cancer during BCG instillation therapy. Here, we intend to evaluate the feasibility of detecting urine samples of bladder cancer patients receiving BCG instillation to predict the bladder cancer recurrence.