As reported in The Lancet Oncology by Brunt et al, long-term follow-up of the UK phase III FAST-Forward trial has shown that a 1-week adjuvant radiotherapy schedule was associated with good outcomes at 10 years in patients with breast cancer.
Study Details
In the multicenter, open-label, noninferiority trial, 4,087 patients were randomly assigned 1:1:1 to receive 40 Gy in 15 fractions over 3 weeks (n = 1,358), 27 Gy in 5 fractions over 1 week (n = 1,362), or 26 Gy in 5 fractions over 1 week (n = 1,367) to the whole breast or chest wall. The primary outcome measure was noninferiority of ipsilateral breast recurrence at 5 years; the primary analysis showed noninferiority in the 26 and 27 Gy groups, with the 26 Gy group having outcomes similar to those in the 40 Gy group. The current analysis reports findings at 10 years and efficacy outcomes in a substudy in patients requiring axillary treatment.
Key Findings
Ipsilateral breast recurrence was identified in 116 patients, including 45 in the 40 Gy group, 41 in the 27 Gy group, and 30 in the 26 Gy group, with respective 10-year cumulative incidence rates of 3.6% (95% confidence interval [CI] = 2.7%–4.9%), 2.9% (95% CI = 2.1%–4.0%), and 2.1% (95% CI = 1.5%–3.1%).
At 10 years, clinician-reported moderate or marked breast or chest wall effects had occurred in 100 (13.1%) of 765 patients in the 40 Gy group, 157 (19.3%) of 814 in the 27 Gy group, and 111 (14.4%) of 770 in the 26 Gy group.
Among 466 eligible patients enrolled in the nodal substudy, median follow-up was 7 years, with a total of 32 locoregional recurrences being reported.
The investigators concluded: “Long-term follow-up confirms that 26 Gy in five fractions over 1 week is safe and efficacious for adjuvant radiotherapy to the breast or chest wall, supporting its use as a standard of care. Efficacy data for this schedule in the axillary nodal radiotherapy setting are reassuring; however, sample size limits precision of estimation for this subgroup on its own.”
Adrian Murray Brunt, FRCR, of Clinical Trials and Statistics Unit, The Institute of Cancer Research, London, is the corresponding author for The Lancet Oncology article.
DISCLOSURE: The study was funded by the UK National Institute for Health and Care Research. For full disclosures of the study authors, visit thelancet.com.
