- A phase 2 trial finds that 5-year outcomes (including OS, 97.3%) are promising for 3 weeks of hypofractionated whole breast irradiation (HF-WBI) that included a sequential boost for patients with early breast cancer.
Why this matters
- This trial is one of the shortest courses of HF-WBI.
- If adopted, costs will be reduced and convenience increased.
- Prospective single-group trial of whole breast dose of 36.63 Gy in 11 fractions of 3.33 Gy, with an equivalent dose to the regional nodes when indicated, followed by a tumor bed boost of 13.32 Gy in 4 daily fractions of 3.33 Gy over a total of 15 treatment days.
- Participants had stage 0-IIIA breast cancer.
- The primary outcome was locoregional control.
- Median follow-up, 62 months.
- 5-year estimated locoregional control was 97.7% (95% CI, 93.0%-99.3%), and distant control was 97.9% (95% CI, 93.6%-99.3%).
- 5-year breast cancer-specific survival was 99.2% (95% CI, 94.6%-99.9%), and OS was 97.3% (95% CI, 91.9%-99.1%).
- Acute and late toxicities:
- Grade 2: 30.1%, 10.1%.
- Grade 3: 0.7%, 3.5% grade 2 and 3 toxicities were seen in 30.1%/10% and 1%/3% of patients, respectively; no grade 4 or 5 toxicities.
- 95.2% of patients had good to excellent cosmesis by physician assessment.
- Nonrandomized, single-group trial.