ASTRO Annual Meeting 2025
BART
ForHigh-risk (T3-4/N+/R+) MIBC, post-cystectomy + chemo, no immunotherapy
HR 0.43
95% CI 0.20-0.96, p=0.04; 2y LRFFS 87.1% vs 76.0% (ITT)
TL;DR2y locoregional FFS 87.1% vs 76.0% (HR 0.43, p=0.04) with adjuvant pelvic RT post-cystectomy; OS not significant (HR 0.78, p=0.31).
Reported via UroToday →
The LRFFS benefit concentrates in the pN+ and T3+ subgroups (2y HR 0.22 and 0.25), and per-protocol it widens to HR 0.27 (93.2% vs 75.0%) once the 14 who never received RT are analysed as observation. Standard 50.4Gy/28fx to bed plus pelvic nodes transfers directly, so this moves the adjuvant-pelvic-RT decision for node-positive or margin-positive disease.
9 details 2 trials watching
Phase 3 multicentre RCT, 1:1, N=153 (RT 77 / obs 76), enrolled 2016-2024, stratified by nodal stage (N0/N+) and chemotherapy. Median follow-up 47 mo. Underpowered: accrual fell short of the sample-size goal.
High-risk (T3-4, N1-3, or R+) non-metastatic urothelial MIBC after radical cystectomy. 62% pT3-4, 41% pN+, 28% variant-histology component; median age 57, median 20 nodes dissected, 4.6% positive margins, 2.6% neobladder.
50.4 Gy / 28 fx to cystectomy bed plus pelvic nodes (common / internal / external iliac, presacral, obturator). Stoma- and bowel-sparing IMRT with daily onboard image guidance.
Primary: 2-year locoregional failure-free survival. Secondary: bladder-cancer-specific survival, DFS, overall survival. Fine-Gray competing-risk analysis (distant mets, non-cancer death).
Primary met; the time-to-event secondaries (DFS, BCSS, OS) all favoured RT numerically but none reached significance.
| Endpoint (2y) | Adjuvant RT | Observation | HR (95% CI), p |
|---|---|---|---|
| LRFFS (ITT) | 87.1% | 76.0% | 0.43 (0.20-0.96), p=0.04 |
| LRFFS (per-protocol) | 93.2% | 75.0% | 0.27 (0.10-0.71), p=0.008 |
| DFS | 71.6% | 58.7% | 0.62 (0.36-1.05), p=0.07 |
| BCSS | 79.6% | 65.0% | 0.59 (0.33-1.10), p=0.09 |
| OS | 70.4% | 57.4% | 0.78 (0.49-1.26), p=0.31 |
| Subgroup | HR (95% CI) |
|---|---|
| T3+ and N+ | 0.25 (0.07-0.84) |
| N+ disease | 0.22 (0.06-0.75) |
| Adverse event | Adjuvant RT | Observation |
|---|---|---|
| Late G3+ | 8.4% | 10.5% (p=0.60) |
| Acute G3 GI | 1.6% | 4.1% |
| Acute G2 GI | 17.5% | 1.4% |
Late grade 3+ toxicity comparable between arms; acute grade 2 GI higher with RT while grade 3 GI was lower, with no toxicity-related discontinuation.
Adjuvant RT after cystectomy is not routine (historic locoregional recurrence ~30% in high-risk pts); BART is the largest RCT in this space. A planned MERCY individual-patient-data meta-analysis will test the OS question.
Underpowered, OS not significant (HR 0.78, p=0.31) on a locoregional surrogate primary. 14/77 RT-arm pts never received RT, so the ITT HR (0.43) understates the per-protocol effect (HR 0.27). No immunotherapy used.
Randomised phase III, prespecified 2y LRFFS primary hit, diverging from the current no-adjuvant-RT norm. Underpowered and OS not significant, so short of practice-changing.
In pN+ or margin-positive high-risk MIBC after cystectomy and cisplatin chemo, this supports weighing adjuvant pelvic RT for locoregional control; it does not establish an OS benefit and does not extend to low-risk node-negative, margin-negative disease.
- OS benefit of adjuvant RT (planned MERCY IPD meta-analysis) n=76 · primary completion 2018-10 · adjuvant EBRT post-cystectomy, ≥pT3 high-riskactive Adjuvant Radiotherapy in Patients With Pathological High-risk Bladder Cancer (GETUG-AFU 30) Phase NAn=81 · primary completion 2027-12 · randomised adjuvant pelvic RT post-cystectomy, survival
- Adjuvant RT plus immunotherapy after cystectomy