Repeat TUR for patients with T1 tumors achieves diagnostic, prognostic, and therapeutic benefit. From a diagnostic standpoint, disease understaging is common for these patients; therefore, a second resection provides a more thorough interrogation for the presence of muscle-invasive disease. Upstaging at repeat resection to muscle-invasive disease has been reported in approximately 30% or more of patients with T1 tumors.157, 164, 165 The risk of upstaging is related to the presence or absence of muscularis propria on the initial resection specimen, with rates of upstaging varying from 40-50% among patients without muscle present on the first TURBT specimen to 15-20% in patients with muscle present at the first TURBT.157 Repeat resection is recommended even when the initial TURBT demonstrates the presence of muscularis propria given the noted risk of upstaging in that setting. Additionally, the pathology at repeat resection contains prognostic value that may guide subsequent clinical management. Patients found to have muscle-invasive disease may be offered neoadjuvant chemotherapy and radical cystectomy as well as tri-modality definitive local treatment. The presence of residual T1 disease at the time of repeat resection is associated with increased recurrence rates and subsequent progression risk approaching 50%.166 As such, these patients should be counseled regarding the potential benefit of early cystectomy.167 Alternatively, patients with non-invasive disease at repeat resection may be considered for initial bladder preservation with intravesical therapy. In terms of a therapeutic benefit, approximately 50-70% of patients with T1 tumors have been reported from prior WLC series to have residual disease at the time of repeat TURBT.157-160 In addition, repeat resection is associated with improved response rates to intravesical BCG therapy, specifically with a decreased risk of subsequent tumor recurrence and progression.168-170 Moreover, a prospective, randomized trial of patients with T1 tumors treated with intravesical mitomycin C demonstrated that repeat TURBT significantly decreased recurrence and progression rates.171 Data suggest that repeat TURBT may reduce overall mortality risk.172 The Panel recognizes that for select patients, repeat TUR is not likely to impact clinical management and may, therefore, be omitted. Some evidence suggests that an initial “complete” resection may be associated with favorable safety and effectiveness outcomes.173 Similarly, patients undergoing en bloc resection may have limited additional benefit from repeat resection.174, 175 Other patients include those with high-risk non-muscle invasive disease who would not be eligible to receive neoadjuvant chemotherapy even if muscle-invasive disease is documented and for whom immediate radical cystectomy is planned. In addition, the role of repeat TUR for patients with pure non-urothelial histology is not well-defined; therefore, management of these patients should be individualized, with consideration given to the specific tumor histology as well as patient comorbidity and renal function status. However, for most patients with T1 or high-risk NMIBC who are candidates for bladder preservation, the preponderance of contemporary evidence supports repeat TURBT because of its value in improving staging accuracy, detecting residual or upstaged disease, determining the existence and extent of CIS, and potentially improving recurrence-free and overall survival outcomes.172, 174