- 5-year results of the FAST-Forward trial show that hypofractionated radiotherapy (RT) delivering 26 Gy in 5 fractions over the course of 1 week is as safe and effective as the standard 3-week course given after primary surgery for early breast cancer.
Why this matters
- Hypofractionated RT is more convenient and less costly to patients.
- Phase 3 noninferiority randomized controlled trial (n=4096) compared 3 regimens:
- 3 weeks of 40 Gy in 15 fractions (40-Gy group);
- 1 week of 27 Gy in 5 fractions (27-Gy group); and
- 1 week of 26 Gy in 5 fractions (26-Gy group).
- Primary outcome was ipsilateral breast tumor relapse.
- Noninferiority was predefined as ≤1.6% excess (HR, 1.81).
- Funding: National Institute for Health Research; others.
- Both hypofractionated protocols were noninferior compared with the 40-Gy regimen for estimated cumulative incidence of ipsilateral breast tumor relapse by 5 years (the primary outcome):
- 27 Gy: 1.7% (HR, 0.86; P=.56).
- 26 Gy: 1.4% (HR, 0.67; P=.15).
- Both hypofractionated protocols were noninferior on safety at 5 years (any adverse event in the breast or chest wall) compared with 40 Gy:
- 27 Gy: 15.9% (OR, 1.55; P<.0001>
- 26 Gy: 12.2% (OR, 1.12; P=.20).