Systematic Review and Meta-Analysis of Response Rates in BCG-unresponsive Non–Muscle-Invasive Bladder Cancer: a Consensus Statement From the International Bladder Cancer Group

Abstract

There is a critical need to establish reference response rates following bladder-sparing therapies administered in the setting of bacillus Calmete-Guerin (BCG)-unresponsive non–muscle-invasive bladder cancer (NMIBC). We sought to determine the efficacy of different interventions in recent trials accruing patients fulfilling the strict BCG-unresponsive definition established by the US Food and Drug Administration. We performed a systematic review and meta-analysis for clinical trials in the BCG-unresponsive disease space to include published and presented results. The primary endpoints were complete response rate for CIS±Ta/T1 tumors, recurrence-free rate for patients with papillary-only disease, and disease-free rate in studies enrolling both papillary CIS tumors (Ta/T1/CIS). I2 was used for assessing heterogeneity. Eleven studies using 9 different therapeutic agents in a total of 909 patients with BCG-unresponsive NMIBC were identified. The resulting outcomes at 3, 6, and 12 months were 44%, 38%, and 25% complete response rate in CIS±Ta/T1 tumors; 73%, 58%, and 48% recurrence-free rate in papillary-only; and 48%, 22%, and 43% disease-free rate in combined Ta/T1/CIS, respectively. Relatively low levels of heterogeneity were observed amongst studies restricted to papillary-only or CIS±Ta/T1 tumors. Future randomized controlled studies are needed and will likely require stratification between papillary-only and CIS±Ta/T1 tumors.

Keywords

• bacillus calmete-guerin
• bcg
• bcg-unresponsive
• bcg refractory
• bcg relapsing
• bladder cancer