The statements and recommendations about the use of hypofractionated radiotherapy for women with early breast cancer are based on a Cancer Australia systematic literature review including available evidence from 2001 to March 2010 from randomised controlled trials. The literature review was undertaken using a systematic method of searching and selection. Searches for full-length publications and abstracts were conducted in EMBASE, Medline and the Cochrane Database of Systematic Reviews. A search of conference websites was also conducted, including the American Society of Clinical Oncology, American Society of Radiation Oncology and San Antonio Breast Cancer Symposium. A total of 682 non-duplicate citations were identified. Following application of the exclusion criteria, a total of 10 citations were identified as eligible for the review. Of the included citations there were two systematic reviews and five randomised controlled trials (some trials were reported by multiple citations).
Five randomised controlled trials, including one conference abstract8 with limited information available, compared the use of one or more hypofractionated radiotherapy regimens to a conventional radiotherapy regimen for women with early invasive breast cancer. The United Kingdom’s Royal Marsden Hospital/Gloucestershire Oncology Centre7, 9 (RMH/GOC) and the Standardisation of Breast Radiotherapy Trial A10 (START A) tested two hypofractionated radiotherapy regimens. A Canadian trial6, 11 and the Standardisation of Breast Radiotherapy Trial B12 (START B) each tested one hypofractionated radiotherapy regimen. In all trials, the conventional radiotherapy regimen used as a comparator was 50 Gy in 25 fractions, delivered over 5 weeks.
A range of hypofractionated radiotherapy regimens were examined, including
- 39 Gy in 13 fractions over 35 days7, 9-10
- 40 Gy in 15 fractions over 21 days12
- 40 Gy in 15 daily fractions8
- 41.6 Gy in 13 fractions over 35 days10
- 42.5 Gy in 16 fractions over 22 days6, 11
- 42.9 Gy in 13 fractions over 35 days7,9
Two trials included women who had undergone breast conserving surgery only.6-7, 9, 11 Three trials included women who had undergone breast conserving surgery or mastectomy.8, 10, 12
In patients who had breast conserving surgery, hypofractionated and conventional radiotherapy regimens were delivered to the whole breast in all five randomised controlled trials.
Median follow-up ranged from 5.1 years (4.4 - 6.0 years) in the START A10 trial to 16.9 years (15.4 - 18.8 years) in the trial by Spooner et al.8