Ductal carcinoma in situ (DCIS)

This factsheet gives information on an early form of breast cancer called ductal carcinoma in situ (DCIS). It explains what it is, how your breast is made up, and how it is treated. For more information, talk to your doctor or nurse or call the National Cancer Helpline on 1800 200 700.

Inside your breasts

Your breasts are made up of ducts, which are tiny tubes that carry milk to your nipple and lobules or glands. These glands make milk for breast feeding and are surrounded by fat and supportive tissues.If the tiny cells that line the walls of the milk ducts change and become abnormal, this can lead to DCIS.

What is DCIS?

DCIS is a very early form of breast cancer. This means that cancer cells have formed inside the milk ducts or ‘in situ’, and have not spread outside your breast. Because DCIS is confined to the breast ducts, it has a very good prognosis (outlook). It is also called precancerous, intraductal or non-invasive cancer. Both women and men can get DCIS but it is very rare in men.

Download the complete Ductal Carcinoma in SItu (DCIS) factsheet (pdf 373 KB).