BCG shortage for intravesical instillation is associated with early tumoral recurrence in patients with high-risk non-muscle invasive bladder tumours

INTRODUCTION

During 2019 there was a worldwide shortage of BCG strains for intravesical instillation, limiting the availability of full dose schemes for maintenance courses. The main objective was to analyze the impact on tumoral relapse secondary to BCG shortage in our center. Secondary outcomes included recurrence and progression-free survival rates and tumoral relapse specific characteristics.

METHODS

Retrospective cohort study including 158 subjects (64 treated during 2019 and 94 during 2017) with high-risk non-muscle invasive bladder cancer and treated with a combination of Transurethral bladder resection (TURB) followed by adjuvant intravesical instillation with BCG in a tertiary hospital in Spain. Basal characteristics of both groups were analyzed. Times to event of interest (relapse; including recurrence and/or progression) were estimated with Kaplan-Meier survival analysis. Disease-free survival rates were analyzed using a multivariable Cox regression model of proportional hazards.

RESULTS

Median follow-up in the 2019 sample was 24 months and 50 months in the 2017 group with a median number of instillations of 8 and 12 respectively. Median time to relapse of 285 days (145-448) during 2019 and 382 days (215-567) in 2017 were observed (logRank p = 0.025). Further multivariable analysis revealed a proportional hazard ratio (HR) for disease-free survival rate of 1.87 (95% CI: 1.04-3.37 p = 0.036). No statistically significant differences in tumoral relapse characteristics were observed.

CONCLUSION

BCG shortage and subsequent reduced-dose schemes used for intravesical instillation due to limited availability, increase early tumoral relapse rates. These findings are consistent with available evidence, showing the need for full-dose BCG courses.

Prognostic significance of pre- and post-treatment PD-L1 expression in patients with primary high-grade non-muscle-invasive bladder cancer treated with BCG immunotherapy

PURPOSE

Programmed cell death-1 ligand-1 (PD-L1) expression has been associated with prognostic implications in urologic malignancies. We aimed to investigate prognostic significance of pre- and post-treatment PD-L1 expression in patients treated with BCG for high-grade non-muscle-invasive bladder cancer (NMIBC).

METHODS

We reviewed a total of 141 high-grade NMIBC cases treated with transurethral resection +  ≥ 6 BCG instillations between 2004 and 2017. PD-L1 immunohistochemistry (IHC) scoring was done on 0-3 scale, and cut-off for positive and high-level PD-L1 expression was set to ≥ 1% and ≥ 5% staining of tumor-infiltrating immune cells (IC), respectively. Clinicopathologic characteristics and oncologic outcomes [recurrence-free (RFS) and progression-free survival (PFS)] were compared, stratified by PD-L1 positivity. The prognostic role of PD-L1 was assessed using Kaplan-Meier, and univariate and multivariate Cox regression analyses.

RESULTS

Pre-treatment, 46.2% and 6.8% of high-grade NMIBC demonstrated positive and high-level PD-L1 expression, respectively. Positive PD-L1 expression was associated with submucosal invasion and refractory-tumor recurrence. PD-L1 expression was not associated with RFS or PFS in regression analysis. Post-treatment, 55.1% and 11.6% of recurrent tumors demonstrated positive and high-level PD-L1 expression, respectively. Down-regulation of PD-L1 expression was noted in patients with refractory recurrence (p = 0.012).

CONCLUSION

Pre-treatment PD-L1 expression was associated with unfavorable pathological features in primary high-grade NMIBC and its expression level after BCG immunotherapy was significantly decreased in patients with refractory recurrence. PD-L1 expression did not have prognostic value for PFS or RFS; therefore, further research is necessary to identify novel biomarkers for prediction of disease outcomes in high-grade NMIBC.