Implications of Guideline-based, Risk-stratified Restaging Transurethral Resection of High-grade Ta Urothelial Carcinoma on Bacillus Calmette-Guérin Therapy Outcomes

BACKGROUND: Guideline indications for restaging transurethral resection (reTUR) for high-grade (HG) Ta bladder tumors vary due to a paucity of data. OBJECTIVE: To investigate guideline-based, risk-adapted approaches to reTUR for HG Ta lesions. DESIGN, SETTING, AND PARTICIPANTS: An institutional review of HG Ta patients who received adequate bacillus Calmette-Guérin (BCG) from 2000 to 2019 was conducted. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Guideline criteria for reTUR were used to stratify patients. Kaplan-Meier product limits estimated survival. Cox regression and log-rank tests identified association of variables with survival. RESULTS AND LIMITATIONS: Of the 209 patients with HG Ta bladder cancer, 104 (50%) underwent reTUR, which identified residual disease in 39 patients (38%). Only one patient (1%) was upstaged to pT1 on reTUR. In all unstratified HG Ta patients, reTUR was associated with improved progression-free survival (p = 0.050) and recurrence-free survival (RFS; p = 0.003). The 5-yr RFS for patients who underwent versus those who did not undergo reTUR based on AUA guidelines was 73% (95% confidence interval 63-81%) versus 52% (40-62%), and for those who underwent versus those who did not undergo reTUR based on EAU guidelines was 76% (61-86%) versus 22% (4-49%). In 45 patients meeting both AUA high-risk criteria (large, multifocal tumors) and EAU criteria (lack of detrusor muscle) for reTUR, lack of restaging was associated with over a two-fold increase in recurrence (67% vs 15%, p = 0.002) and progression (25% vs 6%, p = 0.109). Data were limited by selection bias unaccounted for in selecting candidates for reTUR. CONCLUSIONS: Restaging TUR in all HG Ta patients, regardless of risk stratification, was associated with improved outcomes. The benefit of reTUR was most notable in high-risk patients without muscle in the index specimen, consistent with components of both AUA and EAU guidelines. These data support a non-risk-adapted approach to reTUR for all HG Ta lesions. PATIENT SUMMARY: Restaging bladder tumor resection improves outcomes in patients with high-grade Ta tumors treated with bacillus Calmette-Guérin (BCG).