Ductal carcinoma in situ (DCIS) is an abnormal proliferation of cells in the mammary ducts.

While cells display abnormal cytological features similar to those of invasive breast cancer, unlike invasive breast cancer, DCIS is confined within the duct system. If left untreated, DCIS may increase the risk of developing invasive breast cancer later in life.

The following resources have been designed to assist in decision making by women and their doctors.

Clinical resources

• Understanding ductal carcinoma insitu (DCIS) and deciding about treatment. PDF 763 KB )
  Publication date: 2009.
  A resource for clinicians to support discussions with women diagnosed with DCIS. Online only.