Revisiting Margin Width Guidelines for Ductal Carcinoma In Situ and the Role of Routine Reexcision

Postmenopausal women with hormone receptor–positive ductal carcinoma in situ (DCIS) treated with breast-conserving surgery, whole-breast irradiation, and adjuvant endocrine therapy may not require reexcision to achieve wider surgical margins, as suggested by data from the NSABP B-35 trial. Analysis found small differences in 10-year ipsilateral breast tumor recurrence rates based on margin width, indicating that achieving wider margins (≥ 1 mm or ≥ 2 mm) compared with narrower margins may not justify routine reexcision. These findings prompt reevaluation of margin width guidelines for this specific patient subgroup.