{"entity":{"id":"start-b","kind":"trial","name":"START-B (UK Standardisation of Breast Radiotherapy)","aka":[],"tldr":"START-B showed that three weeks of breast radiotherapy in larger daily doses controls the cancer as well as five weeks of smaller ones, with fewer late changes to the breast, and made 40 Gy in 15 fractions the UK standard.","summary":"START-B randomised 2,215 women with early breast cancer to 40 Gy in 15 fractions or the international standard of 50 Gy in 25. At ten years, local-regional relapse was 4.3 percent with the shorter schedule and 5.5 percent with the standard one, and moderate or marked late normal-tissue effects were less frequent after 40 Gy (Haviland and colleagues, Lancet Oncology 2013, following the 2008 Lancet report). Together with START-A it established that breast cancer is as sensitive to fraction size as normal tissue, the radiobiological basis for hypofractionation.","status":"positive","asOf":"2026-09-16","links":[{"label":"ISRCTN59368779","url":"https://www.isrctn.com/ISRCTN59368779"},{"label":"Lancet Oncology 2013","url":"https://doi.org/10.1016/S1470-2045(13)70386-3"}],"tags":["radiation-wave2"],"related":[],"cancers":["breast-hr-positive","breast-her2-positive","tnbc"],"sections":[],"technologies":["hypofractionated-radiotherapy","imrt-igrt"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["hypofractionation","alpha-beta-ratio"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"notes":[],"phase":"3","setting":"Early breast cancer after surgery: 40 Gy in 15 fractions over three weeks versus 50 Gy in 25 fractions over five weeks","sponsor":"Institute of Cancer Research (UK)","result":"10-year local-regional relapse 4.3% vs 5.5%; fewer late normal-tissue effects with 40 Gy in 15 fractions.","yearReported":2008,"enrolled":2215,"outcomes":[{"endpoint":"Local-regional relapse at 10 years","primary":true,"unit":"%","arms":[{"name":"40 Gy in 15 fractions","n":1110,"value":4.3},{"name":"50 Gy in 25 fractions","n":1105,"value":5.5}]}]},"route":"/trials/start-b/","neighbours":{"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/"}],"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/"}]}}