○ Female, aged ≥ 46 years ○ Screen-detected or incidental micro-calcification ○ Histologically confirmed diagnosis of non-high-grade DCIS confirmed by local pathologist (for ○ both breasts if bilateral disease) by: ○ Small volume core biopsy and Vacuum Assisted Core Biopsy (VACB) ○ Or ○ Vacuum Assisted Core Biopsy (VACB) alone as first line diagnostic approach ○ Or ○ Small volume biopsy or VACB plus open diagnostic surgical biopsy (without clear margins) ○ Or ○ Open diagnostic surgical biopsy (without clear margins) (in accordance with the current NHSBSP Guidelines for Pathology Reporting in Breast Cancer Screening) ○ DCIS diagnosed ≤ 90 days before registration ○ Bilateral DCIS is permitted if non-high grade DCIS is confirmed in both breasts at the time of ○ mammogram and diagnostic biopsy ○ Able to give informed consent and comply with the trial schedule and completion of patient reported outcome questionnaires ○ Patient fit and willing to undergo surgery ○ Written informed consent obtained |