Active Surveillance Noninferior to BCG in High-Grade T1 Bladder Cancer

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European urology Published May 9, 2026 Medically reviewed May 9, 2026 Study authors: Kitamura Hiroshi, Tsukamoto Taiji, Kakehi Yoshiyuki, Mizusawa Junki, Shibata Taro, Sasaki Keita, Tan… PubMed ↗ DOI ↗ By Dr. Julia Lee, PhD · Oncology, Genomics & Drug Development

Key Takeaway

Consider active surveillance as a noninferior option to short-course BCG in highly selected high-grade T1 bladder cancer patients.

This multicenter phase 3 randomized controlled trial enrolled 263 patients with high-grade T1 bladder cancer at initial TURB and no residual tumor at second TURB. Patients were randomized to active surveillance or intravesical BCG for 8 weeks without maintenance therapy.

The primary outcome was invasive relapse-free survival (iRFS). Active surveillance was noninferior to BCG, with a hazard ratio of 0.69 (90% confidence interval 0.44-1.08; p=0.001 for noninferiority). Absolute numbers were not reported.

Safety data showed any-grade adverse events in 50% of the active surveillance group versus 90% in the BCG group. Grade ≥3 serious adverse events occurred in 3.1% and 3.8%, respectively. The safety profile of active surveillance was better than BCG.

Key limitations include that the protocol treatment in the control arm (8 weeks of BCG without maintenance) is not current standard practice. Additionally, the noninferiority finding applies only to this highly selected population.

For clinical practice, active surveillance represents a potentially viable therapeutic strategy for selected patients with high-grade T1 bladder cancer and no residual disease on second TURB, though the control arm limitations should be considered.

Study Details

Study typeRct

EvidenceLevel 2

PublishedMay 2026

PMID41571573

View Original Abstract ↓

BACKGROUND AND OBJECTIVE: We evaluated the noninferiority of active surveillance (AS) in comparison to intravesical bacillus Calmette-Guérin (BCG) in terms of recurrence and progression for patients with high-grade T1 (HG T1) bladder cancer at initial transurethral resection of the bladder (TURB) and no residual tumor at second TURB. METHODS: After initial evaluation, participants diagnosed with HG T1 bladder cancer who had undergone complete eradication of visible tumors underwent a second TURB. Those with specimens showing T0 were randomized to either AS or to intravesical BCG for 8 wk without maintenance therapy. The primary endpoint was invasive relapse-free survival (iRFS). KEY FINDINGS AND LIMITATIONS: In total, 513 participants were enrolled in the initial evaluation. After second TURB, 263 participants were enrolled and randomized. AS was noninferior to BCG in terms of iRFS (hazard ratio 0.69, 90% confidence interval 0.44-1.08; p = 0.001). Rates of adverse events were 50% and 90% for any grade, and in 3.1% and 3.8% for grade ≥3 events in the AS and BCG arms, respectively. The protocol treatment in the control arm was not the current standard. CONCLUSIONS AND CLINICAL IMPLICATIONS: In this highly selected patient population, AS was noninferior to eight-dose intravesical BCG induction therapy in terms of iRFS for T1 disease or deeper intravesical and/or extravesical recurrence. The safety profile of AS was better than that of BCG. These findings indicate that AS represents a potentially viable therapeutic strategy for selected patients with HG T1 bladder cancer for whom second TURB demonstrates the absence of residual disease.