Concurrent Versus Sequential Radiation Dose Escalation to the Surgical Cavity for Conservative Treatment of High-Risk Early Breast Cancer: NRG/RTOG 1005 Phase III Trial.
Summary
In this phase III RCT of 2,255 eligible patients, delivering a concurrent boost during whole-breast irradiation was noninferior to a sequential boost for ipsilateral breast recurrence. Toxicity and cosmetic outcomes were comparable, and overall treatment time was reduced.
Key Findings
- Concurrent boost met noninferiority for ipsilateral breast recurrence with HR 1.31 (90% CI 0.84–2.04).
- 5- and 7-year IBR rates were similar between sequential (2.1%, 2.2%) and concurrent (1.9%, 2.6%) arms.
- Toxicity and cosmetic outcomes were not worsened with concurrent boost, and overall treatment time was reduced.
Clinical Implications
Concurrent boost can be adopted to shorten treatment time in high-risk early breast-conserving therapy while maintaining disease control and cosmetic outcomes, improving patient convenience and resource utilization.
Why It Matters
This large, well-designed RCT directly informs radiotherapy practice, enabling shorter courses without compromising cancer control or cosmetic outcomes.
Limitations
- Noninferiority margin and low event rate may limit detection of small differences in IBR
- Generalizability limited to higher-risk patients and specified WBI regimens/techniques
Future Directions
Evaluate patient-reported outcomes, cost-effectiveness, and applicability in broader risk groups and hypofractionation schemas; explore integration with partial breast irradiation strategies.
Study Information
- Study Type
- RCT
- Research Domain
- Treatment
- Evidence Level
- I - High-quality phase III randomized noninferiority trial with long follow-up
- Study Design
- OTHER