Bladder
First randomised evidence for adjuvant RT after radical cystectomy, though underpowered and analyzed per-protocol.
BART
ForUrothelial MIBC, high-risk (≥pT3 / N+ / R+), post-cystectomy + chemo, M0
TL;DR2yr locoregional FFS 87.1% vs 76.0% with adjuvant RT post-cystectomy, HR 0.43 (0.20-0.96), p=0.04; OS not improved (HR 0.78, ns).
Reported via UroToday →
Why it mattersRadiation oncology
Offer adjuvant pelvic RT (50.4Gy/28fx, cystectomy bed plus iliac/presacral/obturator nodes) to ≥pT3, N+, or margin-positive pts, where benefit concentrates (N+ HR 0.22) and isolated locoregional failure was eliminated. Late grade 3+ toxicity matched observation (8.4% vs 10.5%, p=0.60), answering the late-morbidity fear. Read it as local control: OS was unchanged.
9 details 1 trial watching
Methods
- 🔍 Phase III RCT, N=153 (RT 77 / obs 76), high-risk (T3-4, N1-3, R+) MIBC post-cystectomy + chemo, 2016-2024
- 🔍 RT: cystectomy bed + pelvic nodes (common/internal/external iliac, presacral, obturator), 50.4Gy/28fx, stoma/bowel-sparing IMRT, daily IGRT
CONSORT flow
Randomized 153
↓
Adjuvant RT
allocated 77
analyzed 63
Observation
allocated 76
analyzed 90
Results
- 📊 2yr outcomes, adjuvant RT vs observation (LRFFS primary, rest secondary)
Endpoint (2yr) RT Obs HR (95% CI) p LRFFS 87.1% 76.0% 0.43 (0.20-0.96) 0.04 DFS 71.6% 58.7% 0.62 (0.36-1.05) 0.07 BCSS 79.6% 65.0% 0.59 (0.33-1.10) 0.09 OS 70.4% 57.4% 0.78 (0.49-1.26) 0.31 - 📊 LR recurrence 8% (RT) vs 26% (obs), p=0.006; no isolated locoregional recurrences with RT
- 📊 2yr LRFFS benefit concentrates in high-risk subsets (and per-protocol)
2yr LRFFS analysis/subgroup HR (95% CI) Per-protocol 0.27 (0.10-0.71), p=0.008 T3+ and N+ 0.25 (0.07-0.84) N+ disease 0.22 (0.06-0.75) - 📊 Toxicity, RT vs observation
AE RT Obs p Grade 3 GI 1.6% 4.1% n/a Grade 2 GI 17.5% 1.4% n/a Late grade 3+ 8.4% 10.5% 0.60
Critique
- ⚠️ Primary analysis per-protocol, not ITT: 14 RT-assigned pts (refused 8, progression 4, unfeasible 2) analyzed in observation arm
- ⚠️ Underpowered: trial missed its accrual target
- ⚠️ No immunotherapy given; predates adjuvant nivolumab as SOC, so doesn't address the RT+IO question
Open questions
- OS benefit unconfirmed pending MERCY individual-patient-data meta-analysis
- Adjuvant RT plus immunotherapy combinations with non-overlapping toxicity recruiting Adjuvant Concurrent Immunotherapy and Radiotherapy for the Treatment of Bladder Cancer Phase 1n=10 · primary completion 2027-04 · phase 1 adjuvant concurrent IO + RT safety in bladder
- Generalizability without immunotherapy and in younger cohort (median age 57)
📚 Sources · 📄 1 paper
ASTRO 2025: Bladder Adjuvant Radiotherapy (BART): Clinical Outcomes from a Phase III Multicenter Randomized Controlled Trial
Abstract
ASTRO 2025 phase III Bladder Adjuvant Radiotherapy (BART), Advanced bladder cancer, cystectomy, advanced muscle invasive bladder cancer.
📝 https://www.urotoday.com/conference-highlights/astro-2025/astro-2025-bladder-cancer/163510-astro-2025-bladder-adjuvant-radiotherapy-bart-clinical-outcomes-from-a-phase-iii-multicenter-randomized-controlled-trial.html