{"entity":{"id":"fast-trial","kind":"trial","name":"FAST (5-fraction whole-breast radiotherapy)","aka":["FAST trial","CRUKE/04/015"],"tldr":"FAST is the trial that found the right five-dose schedule by measuring what the breast looked like afterwards. Giving the five treatments one a week, it showed 28.5 Gy leaves the breast no more changed than five weeks of conventional treatment, while 30 Gy leaves it visibly worse.","summary":"FAST recruited 915 women aged 50 or over with low-risk pT1 to pT2 pN0 invasive breast cancer from 18 United Kingdom centres between 2004 and 2007, and randomised them to 50 Gy in twenty-five fractions or to 30 Gy or 28.5 Gy in five once-weekly fractions of 6.0 or 5.7 Gy. Its primary endpoint was not survival or recurrence but change in photographic breast appearance at two and five years, because the question it was built to answer was how large a single fraction the normal breast will tolerate.\n\nFive-year photographs were available for 615 of 862 eligible patients (71 percent). The odds ratio for change in photographic breast appearance against 50 Gy was 1.64 (95 percent confidence interval 1.08 to 2.49, p=0.019) for 30 Gy and 1.10 (0.70 to 1.71, p=0.686) for 28.5 Gy. For any moderate or marked physician-assessed normal-tissue effect the odds ratios were 2.12 (1.55 to 2.89, p<0.001) for 30 Gy and 1.22 (0.87 to 1.72, p=0.248) for 28.5 Gy.\n\nThe estimate that carried the field forward came out of the dose response: an alpha to beta ratio of 2.7 Gy (1.5 to 3.9) for the photographic endpoint, which implies a five-fraction schedule of 28 Gy (26 to 30) is equivalent to 50 Gy in twenty-five. That estimate is why FAST-Forward tested 26 and 27 Gy, and why 26 Gy in five fractions over one week is now the default in England.\n\nCancer outcomes are reported but the trial was never powered for them: at a median 9.9 years there had been eleven ipsilateral breast cancer events (three, four and four across the arms) and 96 deaths.","status":"positive","asOf":"2026-09-25","links":[{"label":"FAST ten-year results (Journal of Clinical Oncology 2020)","url":"https://doi.org/10.1200/JCO.19.02750"}],"tags":[],"related":[],"cancers":["breast-cancer","breast-hr-positive","breast-her2-positive","tnbc"],"sections":[],"technologies":["hypofractionated-radiotherapy","imrt-igrt"],"targets":[],"drugs":[],"companies":[],"institutions":["icr-london"],"pathways":[],"terms":["hypofractionation","alpha-beta-ratio"],"trials":["fast-forward","start-a","start-b"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"phase":"3","setting":"Women aged 50 or over with low-risk invasive breast carcinoma, pT1 to pT2 pN0, after breast-conserving surgery: 30 Gy or 28.5 Gy in five once-weekly fractions against 50 Gy in twenty-five fractions, with change in photographic breast appearance at two and five years as the primary endpoint","sponsor":"Institute of Cancer Research, United Kingdom, funded by Cancer Research UK","result":"At ten years, 28.5 Gy in five once-weekly fractions gave normal-tissue effects no worse than 50 Gy in twenty-five (odds ratio 1.22, 0.87 to 1.72), while 30 Gy was worse (2.12, 1.55 to 2.89); the alpha to beta ratio was estimated at 2.7 Gy.","yearReported":2020,"enrolled":915,"enrolledBasis":"randomised","enrolledNote":"915 women were recruited from 18 United Kingdom centres between 2004 and 2007; the trial carries the Cancer Research UK reference CRUKE/04/015 and no ClinicalTrials.gov registration.","outcomes":[{"endpoint":"Change in photographic breast appearance at 5 years against 50 Gy in 25 fractions","primary":true,"unit":"odds ratio","arms":[{"name":"30 Gy in 5 once-weekly fractions","value":1.64,"note":"95 percent confidence interval 1.08 to 2.49, p=0.019"},{"name":"28.5 Gy in 5 once-weekly fractions","value":1.1,"note":"95 percent confidence interval 0.70 to 1.71, p=0.686"}],"source":"https://doi.org/10.1200/JCO.19.02750"},{"endpoint":"Any moderate or marked physician-assessed normal-tissue effect against 50 Gy in 25 fractions","unit":"odds ratio","arms":[{"name":"30 Gy in 5 once-weekly fractions","value":2.12,"note":"95 percent confidence interval 1.55 to 2.89, p<0.001"},{"name":"28.5 Gy in 5 once-weekly fractions","value":1.22,"note":"95 percent confidence interval 0.87 to 1.72, p=0.248"}],"source":"https://doi.org/10.1200/JCO.19.02750"}],"replication":"FAST-Forward tested 26 and 27 Gy in five daily fractions in 4,096 women and found 26 Gy non-inferior for local control with normal-tissue effects like the three-week standard."},"route":"/trials/fast-trial/","neighbours":{"cancer":[{"id":"breast-cancer","kind":"cancer","name":"Breast cancer (all types)","route":"/cancers/breast-cancer/"},{"id":"breast-her2-positive","kind":"cancer","name":"HER2-positive breast cancer","route":"/cancers/breast-her2-positive/"},{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"technology":[{"id":"hypofractionated-radiotherapy","kind":"technology","name":"Hypofractionated radiotherapy","route":"/technologies/hypofractionated-radiotherapy/"},{"id":"imrt-igrt","kind":"technology","name":"IMRT / IGRT (modern external beam)","route":"/technologies/imrt-igrt/"}],"institution":[{"id":"icr-london","kind":"institution","name":"The Institute of Cancer Research","route":"/institutions/icr-london/"}],"term":[{"id":"alpha-beta-ratio","kind":"term","name":"Alpha/beta ratio","route":"/terms/alpha-beta-ratio/"},{"id":"hypofractionation","kind":"term","name":"Hypofractionation (fewer, larger radiotherapy doses)","route":"/terms/hypofractionation/"}],"trial":[{"id":"fast-forward","kind":"trial","name":"FAST-Forward","route":"/trials/fast-forward/"},{"id":"start-a","kind":"trial","name":"START-A (UK Standardisation of Breast Radiotherapy, trial A)","route":"/trials/start-a/"},{"id":"start-b","kind":"trial","name":"START-B (UK Standardisation of Breast Radiotherapy)","route":"/trials/start-b/"}]}}