DCIS grades and pathology

DCIS is a broad range of conditions, not just one disease.  There are different kinds of DCIS and these can grow at different speeds and in different parts of the breast.

Usually, if you have a diagnosis of DCIS, and doctors want to confirm the diagnosis, they need to test some tissue.

The details are in the pathology report. Knowing this information helps your doctors decide what treatment will be best for you.

About the pathology report

You may have a biopsy to remove some tissue from the suspicious area in your breast. The tissue is sent to a pathologist to be studied under a microscope. The pathologist sends your doctor a pathology report with information about what they found in each sample.

This report contains information about the type and grade of the DCIS. Sometimes it also provides details of:

• the presence of any hormone receptors
• any cell necrosis.

We explain this information below.

Grades of DCIS

Pathologists give DCIS a ‘grade’ to describe the three different types of DCIS. The grade is based on what the DCIS cancer cells look like under a microscope. It shows the level of disease that is present, specifically:

• how similar or different the cells are to normal breast cells
• how quickly they are growing.

The grades are:

• low (grade I) - cells are slow growing and look like normal cells
• intermediate (grade II) – cells grow faster than normal cells and look less like them
• high (grade III) - cells grow quickly and look very different from normal cells.

The size and grade of DCIS can help doctors predict whether the cancer is likely to become invasive.

Unfortunately, no-one can definitely say if a person with DCIS will develop invasive breast cancer in future. We explain the risk of invasive breast cancer after DCIS.

Low-grade DCIS (Grade I)

In low-grade DCIS, the cells are growing slowly and look like normal cells. They may stay as they are without changing (‘dormant’) for many years. It may take, on average, 15 years or more for low-grade DCIS to develop into invasive breast cancer.

Intermediate-grade DCIS (Grade II)

The cells in intermediate-grade DCIS are growing faster than normal cells and look less like them. Like low-grade DCIS, the cells may also stay as they are for many years but in some cases they can develop into invasive breast cancer.

High-grade DCIS (Grade III)

If high-grade DCIS is not treated, is likely to develop into invasive breast cancer. The cells are growing quickly and look very different from normal cells.

The average time for high-grade (fast growing) DCIS to become invasive breast cancer may be around 5 years or less.

Hormone receptor status

The report may also show whether the DCIS cells are positive or negative for hormone receptors. If receptors for the hormones oestrogen or progesterone or both are present, the abnormal cells use on these hormones to grow. This may affect whether hormonal therapies are recommended as a treatment.

Presence of cell necrosis

The pathology report may show that some of the abnormal cells have died. This is called ‘necrosis’, which can mean the cells are turning over more quickly. It happens when cells grow quickly and some cells don’t get enough nourishment and die.

The presence of cell necrosis is important because it shows how fast-growing the DCIS is and may influence treatment decisions.

'Comedo’ necrosis is the name for a large central area of dead cells within the milk duct. It is a sign that abnormal cells are growing fast and uncontrollably.

Resources

There is a lot of confusion about what DCIS is, the terminology, and why treatment can be the same as for an invasive breast cancer. 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

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

For help on how to communicate openly and honestly with your medical team, we have a podcast episode on Communicating with your health professionals.

Questions to ask your team

• Ask your doctor for a copy of your pathology report and other test results. This can help you to ask questions about your diagnosis and gives you a record in case you need it in future.
• If you don’t understand anything in your pathology report, write them down to discuss with your doctor.