○ 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