Moderate hypofractionation remains the standard of care for whole-breast radiotherapy in breast cancer: Considerations regarding FAST and FAST-Forward.
Moderate hypofractionation is the standard of care for adjuvant whole-breast radiotherapy after breast-conserving surgery for breast cancer. Recently, 10-year results from the FAST and 5‑year results from the FAST-Forward trial evaluating adjuvant whole-breast radiotherapy in 5 fractions over 5 weeks or 1 week have been published. This article summarizes recent data for moderate hypofractionation and results from the FAST and FAST-Forward trial on ultra-hypofractionation. While the FAST trial was not powered for comparison of local recurrence rates, FAST-Forward demonstrated non-inferiority for two ultra-hypofractionated regimens in terms of local control. In both trials, the higher-dose experimental arms resulted in elevated rates of late toxicity. For the lower dose experimental arms of 28.5 Gy over 5 weeks and 26 Gy over 1 week, moderate or marked late effects were similar in the majority of documented items compared to the respective standard arms, but significantly worse in some subdomains. The difference between the standard arm and the 26 Gy of the FAST-Forward trial concerning moderate or marked late effects increased with longer follow-up in disadvantage of the experimental arm for most items. For now, moderate hypofractionation with 40-42.5 Gy over 15-16 fractions remains the standard of care for the majority of patients with breast cancer who undergo whole-breast radiotherapy without regional nodal irradiation after breast-conserving surgery.
['Krug|David|D|http://orcid.org/0000-0001-8811-5416', 'Baumann|René|R|', 'Combs|Stephanie E|SE|', 'Duma|Marciana Nona|MN|', 'Dunst|Jürgen|J|', 'Feyer|Petra|P|', 'Fietkau|Rainer|R|', 'Haase|Wulf|W|', 'Harms|Wolfgang|W|', 'Hehr|Thomas|T|', 'Piroth|Marc D|MD|', 'Sedlmayer|Felix|F|', 'Souchon|Rainer|R|', 'Strnad|Vratislav|V|', 'Budach|Wilfried|W|', '|||']
D000818:Animals D001940:Breast D001943:Breast Neoplasms D005260:Female D006801:Humans D000069473:Radiation Dose Hypofractionation D016032:Randomized Controlled Trials as Topic D059039:Standard of Care D016896:Treatment Outcome
Hypofractionation Radiotherapy Breast cancer Local recurrence Late toxicity