Association Between Irrigation Fluid Absorption and Perioperative cfDNA Dynamics After TURBT

This prospective observational cohort study aims to evaluate the association between intraoperative irrigation fluid absorption and perioperative cell-free DNA (cfDNA) dynamics in patients undergoing transurethral resection of bladder tumor (TURBT). Eligible patients with suspected or confirmed bladder cancer scheduled for TURBT will be enrolled. Intraoperative irrigation fluid absorption volume will be recorded, and peripheral blood samples will be collected before surgery and within 24 hours after surgery for cfDNA extraction and mutation analysis. The study will assess whether irrigation fluid absorption volume is associated with changes in cfDNA concentration, tumor-related mutation detection, and clinicopathological features, including tumor stage, grade, size, number, invasion depth, concomitant carcinoma in situ, operative time, resection depth, and intraoperative blood loss. Patients will also be followed for postoperative recurrence, progression, metastasis, and other adverse oncological outcomes. This study may provide preliminary evidence for understanding perioperative tumor-related molecular changes during TURBT and may help improve risk stratification, perioperative management, and postoperative follow-up strategies for patients with bladder cancer.