Ductal Carcinoma In Situ (DCIS)

About 1 in 5 new breast cancers will be DCIS or ductal carcinoma in situ. Nearly all women with this early stage of breast cancer can be cured.

Ductal carcinoma in situ, or DCIS, is also called intraductal carcinoma and Stage 0 breast cancer. DCIS is sometimes called a pre-cancer. It’s a non-invasive or pre-invasive breast cancer. This means the cells that line the ducts have changed to look like cancer cells but they have not spread through the walls of the ducts into the nearby breast tissue.

Because DCIS hasn’t spread into the breast tissue around it, it can’t spread (metastasize) beyond the breast to other parts of the body.

DCIS is considered a pre-cancer because sometimes it can become an invasive cancer. This means that over time, DCIS may spread out of the duct into nearby tissue, and could metastasize. Right now, though, there’s no good way to know for certain which will become invasive cancers and which ones won’t. So all women with DCIS should be treated.

illustration showing details of ductal carcinoma in situ including lobule, duct, normal duct and abnormal cells in duct

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: June 1, 2016 Last Revised: August 18, 2016

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