Ten-year outcomes from a non-inferiority phase 3 trial of partial-breast radiotherapy after breast conservation surgery for early breast cancer

The non-inferiority phase 3 IMPORT LOW trial, at 30 centers in the UK, randomized women after breast conservation surgery for early-stage breast cancer at low risk of ipsilateral breast tumor recurrence 1:1:1 to standard whole-breast radiotherapy (IMRT), reduced-dose radiotherapy, or partial-breast radiotherapy. Ten-year follow-up results showed that reduced-dose and partial-breast radiotherapy are as safe and effective as whole-breast radiotherapy. The authors conclude that these results reaffirm the use of partial-breast intensity-modulated radiotherapy in this population as standard of care.