Background
Phase III RCT (BC-2001). 360 patients with muscle-invasive bladder cancer (T2–T4a) from 45 UK centres. Compared radiotherapy alone vs concurrent chemoradiotherapy (radiotherapy + synchronous 5-fluorouracil and mitomycin C) for bladder preservation. Two-by-two factorial design also examined RT dose fractionation (standard vs reduced high-dose volume). Median follow-up 69.9 months.
Interventions and follow up
Arm A: Radiotherapy (55 Gy in 20 fractions or 64 Gy in 32 fractions) + synchronous 5-FU (500 mg/m² days 1–5 and 16–20) + mitomycin C 12 mg/m² day 1 (n=182)
Arm B: Radiotherapy alone (same dose/fractionation) (n=178)
Primary endpoint: Locoregional disease-free survival
mFollow up: 69.9 month
Arm B: Radiotherapy alone (same dose/fractionation) (n=178)
Primary endpoint: Locoregional disease-free survival
mFollow up: 69.9 month
Results
Locoregional DFS at 5 years: 67% (CRT) vs 54% (RT alone), HR 0.68 (95% CI 0.48–0.96), P=.03
OS at 5 years: 48% (CRT) vs 35% (RT alone) — not statistically significant
Grade ≥3 adverse events (acute): 36.4% (CRT) vs 27.5% (RT alone)
OS at 5 years: 48% (CRT) vs 35% (RT alone) — not statistically significant
Grade ≥3 adverse events (acute): 36.4% (CRT) vs 27.5% (RT alone)
Adverse events
Main adverse events: Grade ≥3 adverse events (any): 36.4% vs 27.5%, P=.07. Grade ≥3 acute bladder events: 13.1% (CRT) vs 6.8% (RT alone). Grade ≥3 bowel events: 9.3% vs 4.5%. No significant increase in late grade ≥3 toxicity with CRT. Treatment-related deaths: 3 (CRT) vs 1 (RT).
Conclusions
The addition of synchronous 5-FU/mitomycin C to radiotherapy significantly improved locoregional control in muscle-invasive bladder cancer compared with radiotherapy alone. BC-2001 is the definitive randomized evidence establishing concurrent chemoradiotherapy (using 5-FU/MMC) as the preferred bladder-preservation regimen over radiotherapy alone.
Key Limitations
Key Limitations: OS benefit was not statistically significant. The 5-FU/MMC regimen, while standard in the UK, differs from cisplatin-based regimens used in North America and tested in RTOG trials, limiting direct cross-trial comparison. Not compared against radical cystectomy. Patients with prior cystoscopic resection of all visible tumor were not required, unlike standard trimodality therapy selection criteria.
Clinical Context
BC-2001 established 5-FU + mitomycin C as a standard radiosensitizing regimen for bladder preservation, particularly in the UK and Europe. NCCN and EAU guidelines cite BC-2001 as key evidence supporting concurrent CRT for MIBC. The choice of cisplatin-based vs 5-FU/MMC CRT depends on patient fitness and institutional preference; both are considered acceptable.
References