Breast Irradiation in Ductal Carcinoma In Situ

There is strong and consistent evidence that whole breast irradiation after breast conserving surgery significantly decreases the risk of ipsilateral breast events, in situ or invasive, underpinning its established role in patients with ductal carcinoma in situ (DCIS). Pending publication of the full results of BIG 3-07/TROG 07.01 randomised trial, addition of tumour bed boost to whole breast irradiation is recommended in the presence of adverse clinical-pathologic features, and the use of moderately hypofractionated whole breast dose-fractionation schedules is supported. As published data supporting the use of adjuvant partial breast irradiation in patients with low-risk DCIS are limited, its off-study application should be limited to low-risk patients defined by international and national guidelines. Finally, low-risk patients may not derive clinically meaningful benefits from radiation therapy and research on molecular profiling is ongoing to improve prognostic precision and guide safe omission of radiation therapy after breast conserving surgery.