- Compared with the standard 3-week regimen, a 1-week hypofractionated regimen of adjuvant whole-breast radiotherapy shows similar efficacy and safety at 5 years in patients with early invasive breast cancer who undergo surgery.
Why this matters
- Hypofractionated radiotherapy is more convenient and cost-effective for patients.
- The Royal College of Radiologists (UK) adopted the 26-Gy schedule as a new standard based on these findings.
- Phase 3 noninferiority randomized controlled FAST-Forward UK trial compared 3 regimens in 4096 patients with early invasive breast cancer:
- 40 Gy in 15 fractions for 3 weeks (standard group).
- 27 Gy in 5 fractions for 1 week (27-Gy group).
- 26 Gy in 5 fractions for 1 week (26-Gy group).
- Primary outcome: ipsilateral breast tumor relapse.
- Noninferiority was predefined as ≤1.6% absolute excess (HR, 1.81).
- Funding: Institute of Cancer Research; others.
- Median follow-up: 71 months.
- Both hypofractionated protocols were noninferior vs the standard regimen for the 5-year rate of ipsilateral breast tumor relapse:
- 27 Gy: 1.7% (HR, 0.88; 95% CI, 0.52-1.50).
- 26 Gy: 1.4% (HR, 0.64; 95% CI, 0.36-1.15).
- Both hypofractionated protocols were noninferior for safety at 5 years (any adverse event in the breast or chest wall) vs standard:
- 27 Gy: OR, 1.55 (P<.001>
- 26 Gy: OR, 1.12 (P=.20).