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Ductal carcinoma in situ (DCIS)

DCIS means that some of the cells lining the breast ducts have started to become abnormal.

What DCIS is

DCIS means that some cells in the lining of the ducts of the breast tissue have started to turn into cancer cells. These cells are all contained inside the ducts. They have not started to spread into the surrounding breast tissue.

Diagram showing ductal carcinoma in situ (DCIS)

Doctors might describe DCIS in different ways. These include pre invasive, non invasive, ductal intraepithelial neoplasia (DIN) or intra ductal cancer.

In some people if DCIS is not treated, it could become an invasive cancer. DCIS and invasive breast cancer are not the same thing.

In invasive breast cancer, the cancer cells have broken out of the ducts and spread into the surrounding breast tissue. There is then a chance that the cells can spread into nearby lymph nodes or other parts of the body.

About DCIS

Around 5,100 people are diagnosed with DCIS in the United Kingdom each year. This includes about 15 men with DCIS each year in the UK.

Symptoms of DCIS

DCIS is diagnosed more often now than in the past. It is often picked up in women when they have mammograms as part of the screening programme. Men do not have a breast screening programme. 

Many people do not have any symptoms when they are diagnosed. A small number of people have

  • a lump in the breast
  • discharge from the nipple which might be blood stained

DCIS grade

The grade of a cancer tells you how much the cancer cells look like normal cells. It gives your doctor an idea of how the cancer might behave and what treatment you need.

DCIS grade is divided into:

  • low grade (more slowly growing)
  • intermediate grade
  • high grade (more quickly growing)

Doctors think that high grade DCIS is more likely to:

  • come back after treatment
  • spread into the surrounding breast tissue (become an invasive cancer)

Treatment for DCIS

Surgery is the main treatment for DCIS. This is the case for most types of breast cancer. You might have surgery to remove:

  • an area of the breast (wide local excision)
  • the whole breast (mastectomy)

Your surgeon might recommend that you have a particular surgery. Or they might give you a choice of operations.

Women have different reasons for choosing a particular operation. For example, some women prefer to keep as much of their breast as possible. Other women prefer to have the whole breast removed as it makes them feel more confident that the DCIS is cured. It is important to discuss your options with your doctor or nurse. 

Removal of part of the breast

Many women have surgery to remove the area of DCIS, with a border of healthy tissue around it. This is called a wide local excision (WLE) or breast conserving surgery, or sometimes a lumpectomy.

After this surgery, you might have radiotherapy to the rest of the breast tissue if the DCIS cells look very abnormal (high grade). The radiotherapy treatment aims to kill off any abnormal cells that may still be within the breast tissue. Your doctor will discuss with you the possible benefits and risks of radiotherapy.

Removal of the whole of the breast

You might have a mastectomy if:

  • the area of the DCIS in your breast is large
  • there are several areas of DCIS in your breast
  • you have small breasts and too much of the breast is affected by DCIS to make wide local excision possible

If you want to, you can choose to have a new breast made (breast reconstruction) at the time of the mastectomy, or sometime afterwards.

Hormone therapy

Doctors continue to research the role of tamoxifen and other hormone therapies as a treatment for DCIS. Trial results have had mixed results.

Some trials suggest that taking tamoxifen after surgery for DCIS reduces the risk of it coming back (recurrence). And can reduce the number of further invasive breast cancers and DCIS. But in these trials, those taking tamoxifen did not live any longer that those who did not take it.

Your doctor might suggest that you have tamoxifen if your DCIS cells have oestrogen receptors.

Follow up

You will have regular check ups once you finish your treatment. Your doctor will examine you and ask about your general health.

This is your chance to ask questions and to tell your doctor if anything is worrying you.

How often you have check ups depends on your individual situation.

Your specialist might suggest yearly mammograms (breast X-rays) until you are invited for 3 yearly mammograms as part of the national breast screening programme. Or if you are already part of the screening programme, you might have yearly mammograms for 5 years.

Trials and research

Trials are looking at the possible causes of DCIS. For example, looking for particular genetic changes that might increase the risk of developing DCIS.

Researchers are also trying to find out whether those with low or intermediate risk DCIS need to have treatment.

Doctors would like to improve existing treatments as well as reduce the side effects. For example, one trial is trying to find out if internal radiotherapy (brachytherapy) is a good as external radiotherapy for DCIS.

Information and help

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About Cancer generously supported by Dangoor Education since 2010.