What causes ductal carcinoma in situ?

These cells multiply within the duct but have not invaded the surrounding breast tissue. DCIS is therefore described as non-invasive, although some untreated areas may later become invasive.

Changes in the cells' genetic instructions disrupt the normal controls on growth and replacement. Hormonal exposure, inherited susceptibility, ageing, and other biological or environmental influences may contribute, but an individual diagnosis usually cannot be traced to one action or event.

DCIS often causes no noticeable breast change and is found when a mammogram shows calcifications. A breast biopsy is needed to examine tissue and confirm the diagnosis; imaging alone cannot determine the cell features.

Your specialist reviews the biopsy findings, including the grade, hormone-receptor information when available, and the estimated extent in the breast. These details, together with your health and preferences, guide a discussion about treatment.

Management may involve removing the affected area with lumpectomy, sometimes followed by radiotherapy. Mastectomy may be discussed when DCIS is extensive or affects separate areas. Hormone therapy may be considered for hormone-sensitive DCIS after surgery.

Arrange a clinical assessment for a new breast lump, bloody nipple discharge, nipple or skin pulling inward, or a persistent change in breast shape or skin. These findings have several possible causes and require examination rather than assumptions about cancer.

After a biopsy or operation, follow the team's wound advice. Seek prompt help for worsening redness or swelling, pus, fever, heavy bleeding, chest pain, or difficulty breathing.

Ask what the pathology report says about grade and extent, whether more imaging is needed, which surgical options fit the location, and whether radiotherapy or hormone therapy could add benefit. Also ask how each choice may affect follow-up, breast appearance, and recovery.