Do we need repeat transurethral resection after en bloc resection for pathological T1 bladder cancer?

OBJECTIVES: To assess the clinical significance of repeat transurethral resection (reTUR) and surgical margin status after en bloc resection of bladder tumour (ERBT) for pathological T1 (pT1) bladder cancer. PATIENTS AND METHODS: We retrospectively analysed the record of 106 patients with pT1 high‐grade bladder cancer who underwent ERBT between April 2013 and February 2021 at multiple institutions. All specimens were reviewed by a genitourinary pathologist. The primary outcome measures were recurrence‐free survival (RFS) and progression‐free survival (PFS) between patients with and those without reTUR. We also analysed the predictive value of surgical margin on the likelihood of residual tumour on reTUR. RESULTS: A reTUR was performed in 50 of the 106 patients. The 2‐year RFS and 3‐year PFS were comparable between patients who underwent reTUR and those who did not (55.1% vs 59.9%, P = 0.6, 80.6% vs 82.6%, P = 0.6, respectively). No patient was upstaged to pT2 on reTUR. Regarding the surgical margin status, there were no recurrences at the original site in 51 patients with negative horizontal margins. Cox proportional hazard analysis revealed that a positive vertical margin was an independent prognostic factor of worse PFS. On reTUR, six pTa/is residues were detected in patients with a positive horizontal margin, and three pT1 residues were detected in one patient with a positive vertical margin or other adverse pathological features. CONCLUSIONS: A reTUR after ERBT for pT1 bladder cancer appears not to improve either recurrence or progression. Surgical margin status affects prognosis and reTUR outcomes. A reTUR can be omitted after ERBT in patients with pT1 bladder cancer and negative margins; for those with positive horizontal or vertical margins, reTUR should remain the standard until proven otherwise.