Immediate radical cystectomy versus BCG immunotherapy for T1 high-grade non-muscle-invasive squamous bladder cancer: an international multi-centre collaboration.

Purpose: To compare cancer-specific mortality (CSM) and overall mortality (OM) between immediate radical cystectomy (RC) and Bacillus Calmette-Guérin (BCG) immunotherapy for T1 squamous bladder cancer (BCa).

Methods: We retrospectively analysed 188 T1 high-grade squamous BCa patients treated between 1998 and 2019 at fifteen tertiary referral centres. Median follow-up time was 36 months (interquartile range: 19-76). The cumulative incidence and Kaplan-Meier curves were applied for CSM and OM, respectively, and compared with the Pepe-Mori and log-rank tests. Multivariable Cox models, adjusted for pathological findings at initial transurethral resection of bladder (TURB) specimen, were adopted to predict tumour recurrence and tumour progression after BCG immunotherapy.

Results: Immediate RC and conservative management were performed in 20% and 80% of patients, respectively. 5-year CSM and OM did not significantly differ between the two therapeutic strategies (Pepe-Mori test p = 0.052 and log-rank test p = 0.2, respectively). At multivariable Cox analyses, pure squamous cell carcinoma (SqCC) was an independent predictor of tumour progression (p = 0.04), while concomitant lympho-vascular invasion (LVI) was an independent predictor of both tumour recurrence and progression (p = 0.04) after BCG. Patients with neither pure SqCC nor LVI showed a significant benefit in 3-year recurrence-free survival and progression-free survival compared to individuals with pure SqCC or LVI (60% vs. 44%, p = 0.04 and 80% vs. 68%, p = 0.004, respectively).

Conclusion: BCG could represent an effective treatment for T1 squamous BCa patients with neither pure SqCC nor LVI, while immediate RC should be preferred among T1 squamous BCa patients with pure SqCC or LVI at initial TURB specimen.