About DCIS

A diagnosis of DCIS (ductal carcinoma in situ) is not a diagnosis of invasive breast cancer. There are different kinds of DCIS and these can grow at different speeds (the grade) and in different parts of the breast.

In itself, DCIS isn’t life threatening. However, having DCIS can increase your risk of developing invasive breast cancer later in life.

In Australia, around 1,500 women are diagnosed with DCIS each year (BreastScreen monitoring report, 2023).

What is DCIS?

A diagnosis of DCIS means some of the milk ducts in your breast contain abnormal cells. These abnormal cells have not spread from your ducts into your breast tissue or other parts of the body (the term in situ means ‘in place’).

This means DCIS has a very good chance of cure.
A pathology report gives information about the type and grade of the DCIS. This information will help your doctors make treatment recommendations for you.

To understand what is in a pathology report, go to DCIS grades and pathology.

DCIS is described in many different ways, which can make people confused and afraid. These terms all mean DCIS:

• non-invasive tumour
• pre-cancer or pre-malignant cells
• a precancerous condition
• stage 0 breast cancer
• intraductal carcinoma (mostly US)
• breast abnormality.

See How DCIS develops in the breast to understand what a breast looks like from the inside.

Treatment for DCIS is important. You might feel confused about why DCIS is treated like invasive breast cancer when it is not invasive.

If DCIS is not treated, it can spread outside the ducts into surrounding breast tissue. From there, it can travel to other parts of the body. When this happens, it becomes invasive breast cancer.

Resources

There is a lot of confusion about what DCIS is, the terminology, and why treatment can be so major. We have resources to help you understand the symptoms and diagnosis, possible treatments and the relationship between DCIS and breast cancer.

• Ductal carcinoma in situ (DCIS) booklet
• Podcast: DCIS

For help on how to communicate openly and honestly with your medical team, our Let’s be Upfront podcast series has an episode on Communicating with your health professionals.

Cancer Australia provides evidence-based information on DCIS, diagnosis, symptoms and treatment.