Ductal carcinoma in situ (DCIS)

DCIS is an early form of breast cancer.

Breast cancer starts when cells in the breast begin to divide and grow in an unusual and uncontrolled way.

Breasts are made up of milk-producing glands (lobules) and tubes that carry milk to the nipple (ducts). These are surrounded by tissue that gives the breasts their size and shape.

When cancer cells have developed in the ducts and stay in the ducts (in situ), it’s called DCIS. The cancer cells aren’t yet able to spread outside these ducts into the surrounding breast tissue or to other parts of the body. As a result, DCIS has a very good prognosis (outlook).

You may hear DCIS described in different ways such as:

• Pre-invasive
• Intraductal
• Non-invasive
• In situ cancer
• Stage 0 breast cancer

DCIS usually has no symptoms. Most cases of DCIS are found during routine breast screening or if you have a mammogram for another reason.

Sometimes DCIS is found if you have a breast change, such as a lump or discharge (liquid) from the nipple. However, if you’re diagnosed with DCIS after noticing a breast change, it’s more likely you’ll also have an invasive breast cancer.

Some people with DCIS also have a rash involving the nipple known as Paget’s disease of the breast, although this is rare.

DCIS is diagnosed using a range of tests. These may include:

• A mammogram
• An ultrasound scan
• A core biopsy
• A vacuum assisted biopsy 

Find out more about the tests you may have at the breast clinic.

Diagnosing calcifications

If you have no symptoms but are asked to come back to the breast clinic after you’ve had a mammogram, it may be because some tiny white dots were seen on the mammogram.

These white dots are spots of calcium salts called calcifications. Calcifications can sometimes be due to DCIS, but this is not always the case. Many women develop benign (not cancer) calcifications in their breasts as they get older.

If you have calcifications, you’ll have more mammograms to see the calcifications in more detail. Sometimes you’ll also have an ultrasound. Depending on the results, you may need more tests to find out if the calcifications are benign (not cancer).

Inserting a metal marker

If you have a biopsy, a small metal clip called a marker may be placed in the breast where the biopsy samples were taken. This is so the area can be found again if another biopsy or surgery is needed. The marker can safely be left in the breast and does not need to be removed, even if you don’t need any more procedures.

DCIS is graded based on what the cells look like under the microscope. They’re given a grade according to how different they are to normal breast cells and how quickly they are growing. DCIS is graded as:

• Low grade – the cancer cells look most like normal breast cells and are usually slower growing
• Intermediate grade – the cancer cells look less like normal breast cells and are growing faster than low grade
• High grade – the cancer cells look different to normal breast cells and may be fast growing

In some cases, DCIS will never develop further or grows so slowly that it would never cause harm during a person’s lifetime.

Can DCIS develop into invasive breast cancer?

If DCIS is not treated, the cancer cells may develop the ability to spread outside the ducts into the surrounding breast tissue. This is known as invasive breast cancer. Invasive breast cancer also has the potential to spread to other parts of the body.

Although the size and grade of the DCIS can help guide if it will become invasive, there is currently no way of knowing if this will happen.

Getting your results

The staff at the clinic will tell you how and when you’ll get your biopsy results. You’ll usually be given an appointment to return to the clinic for your results.

Treatment is usually recommended for DCIS. This is because there’s no way of knowing when or if DCIS will become invasive. It’s possible this may lead to unnecessary treatment for some people.

Your treatment team will discuss the benefits and possible risks of treatment with you.  

The aim of treatment is to remove all the DCIS from the breast to reduce the chance of it becoming an invasive cancer.

If you have any questions or concerns about your diagnosis and treatment, talk to your treatment team.

Surgery

Surgery is usually the first treatment for DCIS. This may be breast-conserving surgery or a mastectomy.

You’re more likely to be recommended a mastectomy if:

• The DCIS affects a large area of the breast
• The DCIS is in more than 1 part of the breast (although if the areas are small, it may be possible to have 2 lumpectomies instead of a mastectomy)
• The area has been removed but it hasn’t been possible to get a clear margin of normal tissue around the DCIS using lumpectomy

A nipple-sparing mastectomy may be possible in some cases. You may wish to ask your treatment team about this.

If you’re not recommended a mastectomy but you would prefer to have one, you can discuss this with your treatment team.

You may be offered a choice between these types of surgery, depending on the size of the DCIS and where it is in your breast. Your treatment team will discuss this with you.

A doctor called a pathologist will look at the breast tissue removed during surgery under a microscope. If they see any DCIS cells at or close to the margin of normal breast tissue, you may need more surgery.

Occasionally, an area of invasive breast cancer may also be found with the DCIS. If this is the case, your treatment team will discuss further treatment options with you.

Breast reconstruction

If you have a mastectomy, you’ll usually be able to have breast reconstruction. This can be done at the same time as your mastectomy (immediate reconstruction) or months or years later (delayed reconstruction).

Some women choose not to have, or cannot have, breast reconstruction. They may use a breast prosthesis or may prefer not to use anything.

Marking the area of DCIS

As most cases of DCIS can’t be felt, the exact position is usually “marked” for the surgeon so they can remove the right area.

The area may be marked by:

• A fine wire (called wire localisation)
• A small low-dose radioactive seed
• A small radiation-free magnetic marker

If the wire, seed or magnet feels uncomfortable while it’s in place, you can have mild pain relief like paracetamol.

Wire localisation 

Using a mammogram or ultrasound scan as a guide, a fine wire will be inserted into the breast under local anaesthetic (medication to numb the area). The wire is then carefully secured under a small dressing and left in place until the surgery to remove the area of DCIS.

You may have the wire inserted on the same day as the surgery to remove the DCIS. Or you may have the wire inserted as an outpatient the day before the surgery to remove the DCIS.

The wire will be removed during the surgery to remove the DCIS.

After your operation you may have some soreness and discomfort, but this can be managed with pain relief. There will be a scar, but this should fade in time.

Seed or magnet

You may have a low-dose radioactive seed or a radiation-free magnet inserted into the breast tissue. This can be done several weeks before the surgery to remove the DCIS.

During surgery, a special probe is used to locate the seed or magnet and guide the surgeon to the tissue that needs to be removed. The seed or magnet will be removed during the operation.

After your operation you may have some soreness and discomfort, but this can be managed with pain relief. There will be a scar, but this should fade in time.

Surgery to the lymph nodes under the arm

Lymph node (gland) removal is not usually recommended for people with DCIS. This is because the cancer cells haven’t developed the ability to spread outside the ducts into the surrounding breast tissue, so would not have spread to the lymph nodes.

Sentinel lymph node biopsy

If you’re having a mastectomy, your treatment team will discuss having a sentinel lymph node biopsy at the same time.

If you have breast-conserving surgery for DCIS, you will not usually be offered sentinel lymph node biopsy unless you have a high risk of invasive disease, for example if you have a lump or a large area of calcifications on the mammogram. Your treatment team will discuss with you whether you need sentinel lymph node biopsy.

Find out more about surgery to the lymph nodes.

Other treatments

After surgery, you may need other treatments. These are called adjuvant treatments and can include radiotherapy and, in some cases, hormone (endocrine) therapy.

The aim of these treatments is to reduce the risk of DCIS coming back or an invasive cancer developing.

Chemotherapy and targeted therapy are not used as treatment for DCIS.

Radiotherapy

Radiotherapy uses high energy x-rays to destroy cancer cells. 

If you have breast-conserving surgery, you’ll usually be offered radiotherapy to the breast.

You won’t usually need radiotherapy after a mastectomy for DCIS.

Hormone (endocrine) therapy

Some breast cancers use oestrogen in the body to help them to grow. These are known as oestrogen receptor positive or ER-positive breast cancers.

Hormone therapies block or stop the effect of oestrogen on breast cancer cells. Different hormone therapy drugs do this in different ways.

DCIS may be tested to see if it’s ER-positive.

Some studies have found taking hormone therapy after surgery reduces the risk of DCIS coming back (recurrence) and the risk of invasive breast cancer developing.

The benefits of hormone therapy for people with ER-positive DCIS depend on what other treatment you have. It’s not recommended for everyone.  If your DCIS is ER-positive, your treatment team will discuss the benefits, risks and possible side effects of hormone therapy with you.  

If oestrogen is not helping your DCIS grow, it’s ER-negative and hormone therapy will not be of benefit.

Follow-up

You will continue to be monitored after your hospital-based treatments finish. This is known as follow-up.

If you had breast-conserving surgery, follow-up will include regular mammograms to both breasts.

If you had a mastectomy, you’ll have a mammogram on your other breast.

How you’re followed up after treatment will also depend on your age and the arrangements at the hospital where you’ve been treated.

Checking for changes

It’s important to be aware of any changes to the breast, chest or surrounding area, whether you had breast-conserving surgery or a mastectomy (with or without reconstruction).

It can be difficult to know how your breast or scar area should feel. The area around the scar may feel lumpy, numb or sensitive.

This means you’ll need to get to know how it looks and feels so you know what’s normal for you. This will help you to feel more confident about noticing changes and reporting them early to your GP or treatment team.

It’s also important to be aware of any new changes in your other breast and report them as soon as possible.

If you have any concerns, speak with your GP or treatment team.

Being told you have DCIS can be a worrying time. Everyone reacts differently to their diagnosis and has their own way of coping.

Although DCIS has a very good prognosis, it’s normal to feel anxious. Because DCIS is an early form of breast cancer, some people feel less able to ask for help with their worries.

But there are people who can support you, so don’t be afraid to ask for help if you need it. By letting other people know how you feel, particularly your family and friends, they can be more supportive.

Some people find it helpful to discuss their feelings and concerns with their treatment team. If you’d like to talk it through in more depth, a counsellor or psychologist may be more appropriate. Your treatment team or GP can arrange this.

You might want to speak to someone who knows what it’s like. Our Someone Like Me service can put you in touch with someone who’s had a similar experience to you, so you can talk through your worries and share experiences over the phone or by email. 

You can also call our helpline or send us a message to speak to one of our nurses about your questions or concerns. See below for ways to get in touch.