Impact of re‐transurethral resection of bladder staging on risk stratification of high‐grade <scp>T1</scp> non‐muscle‐invasive bladder cancer across European Association of Urology 2021 risk groups

Residual T1 at re-TURB is strongly associated with adverse long-term oncological outcomes in BCG-treated T1HG NMIBC and markedly reduces the likelihood of statistical cure. High- and very high-risk patients with persistent T1 represent a biologically adverse subgroup in whom standard BCG may be insufficient.