Ductal carcinoma in situ (DCIS)

DCIS is an early breast cancer. It 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.

Doctors might describe DCIS in different ways. These include:

• pre invasive
• non invasive
• ductal intraepithelial neoplasia (DIN)
• 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.

How common is DCIS?

Around 7300 women are diagnosed with DCIS in the UK each year. 

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 UK breast screening programme. Men don't have a breast screening programme because DCIS and breast cancer are so rare in men. 

Many people don't 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
• a rash on the nipple that may be red and scaly

DCIS grade and stage

Doctors use the grade and stage of a cancer to help them decide which treatment you need. Grading means how abnormal the cells look under a microscope. Staging means how big the cancer is and how far it has spread.

Grade

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)

Stage

DCIS is a pre invasive breast cancer. The cancer cells are in breast ducts and have not started to spread into the surrounding breast tissue.

There are different ways of staging breast cancer. In the UK, the most common one is the TNM system. You might also be told about the number system.

The TNM staging system stands for Tumour, Node, Metastasis.

• T describes the size of the tumour (cancer)
• N describes whether the cancer has spread to the lymph nodes 
• M describes whether the cancer has spread beyond the lymph nodes to a different part of the body

In the TNM staging system, DCIS is the same as Tis N0 M0.  

The number staging system divides cancers into 5 stages, from 0 to 4. In the number staging system, DCIS is stage 0.

Treatment for DCIS

Surgery is the main treatment for DCIS.

You might have surgery to remove:

• an area of the breast (breast conserving surgery)

• the whole breast (mastectomy)

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

You may have different reasons for choosing a particular operation. For example, some people prefer to keep as much of their breast as possible. Others prefer to have the whole breast removed because it makes them feel more confident that the DCIS has been removed.

It is important to discuss your options with your doctor or nurse. 

Surgery to remove just an area of DCIS

Many people have surgery to remove the area of DCIS and a border of healthy tissue (a margin) around it. This is called breast conserving surgery, or a wide local excision (WLE) 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 might still be in the breast tissue. Your doctor or breast care nurse will discuss with you the possible benefits and risks of radiotherapy.

Removal of the whole breast

You might have a mastectomy if:

• the area of the DCIS is large
• there are several areas of DCIS
• you have small breasts and too much of the breast is affected by DCIS to make breast conserving surgery possible

You may have surgery to your armpit called a sentinel lymph node biopsy if you have a mastectomy. This means having about 1 to 3 lymph nodes removed to see if they contain cancer cells. 

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

Hormone therapy

Hormone therapy is recommended for 5 years if you have breast conserving surgery for DCIS and:

• your cancer cells have oestrogen receptors (oestrogen positive)

• you do not have radiotherapy

Research shows that taking hormone therapy after breast conserving surgery for DCIS reduces the risk of it coming back (recurrence). 

Trials show that hormone therapy can reduce the number of further invasive breast cancers or DCIS. But in these trials, the people taking a hormone therapy tablet called tamoxifen did not live any longer than those who didn't take it.

Follow up

After treatment you usually have regular check ups. At the check ups your doctor or a breast care nurse will examine you and ask about your general health. This is your chance to ask questions and to tell them if anything is worrying you.

How often you have check ups depends on your individual situation but you might have them for at least 5 years. This might include yearly mammograms . 

It’s important to remember that you can contact your doctor or nurse between appointments if you are worried about a symptom or have questions. You don't have to wait for your next appointment. You can also speak to your GP.

In some hospitals you don't have regular appointments after treatment. But if you have new symptoms or are worried about anything you can phone your doctor or breast care nurse or make an appointment to see them. 

UK guidelines say that everyone who has had treatment for early breast cancer should have a copy of a written care plan. The care plan has information about tests you will have, and signs and symptoms to look out for. It will also include contact details for specialist staff, such as your breast care nurse.

How likely is DCIS to come back?

The chance of the DCIS coming back depends on various factors. But after mastectomy DCIS almost never comes back. In women who have just the area of DCIS removed the chance of it coming back is a bit higher. But it depends on the grade and type of DCIS.

Your doctor can give you more information about the chance of the DCIS coming back in your case.

Research and clinical trials

One clinical trial looked at the possible causes of DCIS. In particular, genetic changes that might increase the risk of developing it. The study team concluded that there may be some evidence that there is a genetic cause of DCIS and invasive breast cancer. But more research is needed.

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

Coping with DCIS

Coping with DCIS can be difficult. There is help and support available to you and your family.