What is DCIS?

DCIS is the earliest changes to cells which might then become breast cancer. It is not a life-threatening condition. But treatment is usually recommended to stop it developing into breast cancer.

Breast cancer usually starts in the cells that line the:

  • lobules, where milk is made
  • ducts that carry milk from the lobules out through the nipple.

In DCIS, the lining of the lobules and ducts is replaced by abnormal cells. The cells are completely contained in the ducts and lobules. They have not broken through the walls of the lobules or ducts, and they have not spread into surrounding breast tissue. This is because the cells are not yet able to invade other tissue.

Side view of breast


The side view of the breast
Image: This shows a cross section of the breast. It shows the muscle layer behind the breast and the fatty tissue in the breast. Within the fatty tissue are the lobes and ducts, which connect to each other and to the nipple. The lobes are irregularly shaped. The ducts are thinner and tube-like. In one duct, there is a shaded area that shows localised DCIS. The shading is completely within the duct. In another duct, there is some shading which spreads into the fatty tissue. This shows an invasive cancer.

DCIS is the earliest changes to cells which might then become breast cancer. It is not a life-threatening condition. But treatment is usually recommended to stop it developing into breast cancer.

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DCIS and invasive breast cancer

If DCIS is not treated, over time there may be more changes to the cells. This means it may spread into (invade) the breast tissue surrounding the ducts. It then becomes an invasive breast cancer

Not every untreated DCIS will develop into invasive breast cancer. But doctors usually advise treating DCIS. This is because it is not possible to tell for certain which cases of DCIS will become invasive cancer.

Having DCIS means you have a slightly higher risk of getting cancer elsewhere in the same breast or in your other breast.

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Symptoms of DCIS

DCIS usually has no symptoms. It is usually found through changes seen on a mammogram. Mammograms are used as part of the NHS breast screening programme.

A small number of people go to their GP with symptoms and are referred for a mammogram. Symptoms include:

  • a breast lump
  • discharge from the nipple
  • an eczema-like rash on the nipple

Always see your GP if you have any of these symptoms or any other breast symptoms.

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Causes of DCIS

The exact cause of DCIS is unknown. But certain things can increase the chance of developing it. These are called risk factors. The risk factors for DCIS and invasive breast cancer are similar.

Having 1 or more risk factors does not mean you will definitely get DCIS. And if you do not have any risk factors, it does not mean you will not get DCIS.

DCIS is likely to be caused by a combination of different risk factors, rather than just 1 risk factor.

Diagnosis of DCIS

DCIS is usually found through changes seen on a mammogram as part of the NHS breast screening programme. This means DCIS is now diagnosed much more often than it used to be. In the UK, 1 in 5 breast cancers found by screening are DCIS (20%). 

The NHS breast screening programmes aim to find breast cancer very early. This means you have the best chance of the cancer being cured. In the UK, women, and people assigned female at birth, aged 50 to 70 are invited to attend breast screening every 3 years.

A small number of women go to their GP with symptoms and are referred for a mammogram. Always see your GP if you have any breast symptoms.

If you have Paget’s disease, you may also have DCIS. This means you will usually be referred for a mammogram. Paget’s disease is a condition that affects the skin of the nipple. It causes redness, discharge or bleeding and sometimes itching of the nipple and the darker area around it (areola).

Further tests

If a mammogram shows changes, you will be referred to a breast clinic for further tests. The clinic staff will explain why you have been invited back and which tests you need. You may be able to have the tests on the same day. But sometimes you have to come back for further tests.

  • Mammograms

    You may have more mammograms that focus on the area of DCIS. These can be taken from different angles or use magnification.

  • Breast ultrasound

    An ultrasound uses sound-waves to build up a picture of the breast tissue. You will also have an ultrasound on the lymph nodes in the armpit. 

  • Breast biopsy

    There are different ways you may have a biopsy. The doctor removes a small piece of tissue or a sample of cells from the lump or abnormal area. The sample is then checked for cancer cells.

The clinic staff will let you know how and when you will get your results. You are usually given an appointment to come back for your results.

Planning treatment for DCIS

Your cancer doctor needs certain information about the DCIS to help plan the best treatment for you. This includes:

Treatment for DCIS

A team of specialists will meet to discuss the best possible treatment for you. This is called a multidisciplinary team (MDT).

After the MDT, your cancer doctor or specialist nurse will talk to you about the treatment options. They will explain the different treatments and their side effects. They will also talk to you about the things you should consider when making treatment decisions. You can decide together on the best treatment plan for you. 

The main treatment is surgery to remove the DCIS. Not all DCIS will develop into invasive breast cancer. The aim of treatment is to remove it and reduce the risk of it developing into invasive cancer.

You may also be offered other treatments such as radiotherapy and hormonal therapy.


Surgery is the main treatment for DCIS. The operation you have depends on:

  • the size of the DCIS
  • the position of the DCIS
  • what you prefer.

Your surgeon and breast care nurse will talk to you about your options. You may be asked to decide which operation you have.

The most common type of surgery for DCIS is breast-conserving surgery. This surgery aims to keep as much of the breast and its shape as possible.

Your surgeon may advise you to remove the whole breast (mastectomy). If you have a mastectomy, you will usually have a sentinel lymph node biopsy (SNLB). This is a way of checking a few lymph nodes in the armpit for cancer cells.

If you have a mastectomy, you may be able to have a new breast shape made during the operation. This is called breast reconstruction. You can choose to have it done later.

A WLE and a mastectomy work equally well for treating DCIS. This means your surgeon and breast care nurse may ask you to decide which type of surgery you feel is right for you.

We have more information on what to expect from your operation. You may need support when dealing with changes to your body after surgery.

Other treatments

You may also have other treatments:

  • Radiotherapy

    After breast-conserving surgery, your cancer doctor will usually advise you to have radiotherapy to reduce the risk of DCIS coming back.

  • Hormonal therapy

    Hormones help control how cells grow and what they do in the body. The hormone oestrogen can encourage some breast cancers to grow. This may also happen with the hormone progesterone.

    Hormonal therapy reduces the amount of oestrogen in the body or stops it attaching to cancer cells. It only works for breast cancer that is oestrogen receptor positive (ER positive). Hormonal therapy is also called endocrine therapy.

    Hormonal therapy is commonly used to treat invasive breast cancer. This is because it reduces the risk of breast cancer coming back. Hormonal therapy can also reduce the risk of DCIS coming back. But the benefits may not always outweigh the side effects.

    Your cancer doctor will explain the possible benefits and disadvantages of hormonal therapy in your situation. The type of hormonal therapy you have depends on whether you have been through the menopause.

After DCIS treatment


After treatment, you will have yearly mammograms for 5 years. If you had a mastectomy, the mammogram will be of your other breast.

After 5 years, if you are 50 or over, you usually have mammograms through the NHS breast screening programmes. Younger women usually continue to have yearly mammograms after the first 5 years, until they reach 50.

You may get anxious between appointments. This is natural. It may help to get support from family, friends or a support organisation. 

Macmillan is also here to support you. If you would like to talk, you can: 

Be aware of changes

Your treated breast will look and feel different. Your nurse can tell you what you to expect and what to check for. It is also important to be aware of what to look out for in your untreated breast. You can read more about symptoms of breast cancer.

Sex life after DCIS

DCIS and its treatments and side effects may affect your sex life and how you feel about yourself (body image).

Difficulties often slowly improve after treatment, but it can sometimes take longer. You may feel insecure and worry about your current or future relationships.

If you have a partner, you may feel insecure about whether they will still find you sexually attractive. It can help to try to talk about it with them. You may both need some time to adjust.

Let your doctor or nurse know if any difficulties with your sex life do not improve. They may be able to reassure you or offer further help and support. If you feel uncomfortable talking to your doctor or nurse, you can call us for free on 0808 808 0000.

Some people may find it helpful to talk to a sex therapist. You can contact a therapist through the College of Sexual and Relationship Therapists.

We have more information about sex and cancer.


Your cancer doctor or nurse will usually advise you not to use contraception that contains hormones. This includes the pill or implants that release hormones. Your GP can give you advice about suitable methods of contraception. These may include:

  • coils (intra-uterine devices) that do not contain hormones
  • barrier methods such as condoms
  • diaphragms or caps.

Mirena® coil

The Mirena® coil works by releasing a small amount of a hormonal medicine into the womb. The medicine is called levonorgestrel. It is an artificial type of progesterone. Doctors are unsure how much of it reaches other parts of the body after it has been released into the womb.

Studies have tried to find out if the Mirena coil could cause cancers that depend on hormones to grow. The results have been mixed. But there is currently no strong evidence to show that the Mirena coil encourages these types of cancer to grow. Because it contains progesterone, it is not usually recommended for people who have had cancers that depend on hormones to grow. This includes breast cancer.

If you are concerned, you can talk to your GP or specialist about what contraception is best for you.

Well-being and recovery

Even if you already have a healthy lifestyle, you may choose to make some positive lifestyle changes after treatment.

Making small changes to the way you live such as eating well and keeping active can improve your health and well-being and help your body recover.

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About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Professor J Michael Dixon, Professor of Surgery and Consultant Surgeon.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

  • use plain English
  • explain medical words
  • use short sentences
  • use illustrations to explain text
  • structure the information clearly
  • make sure important points are clear.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

You can read more about how we produce our information here.

Date reviewed

Reviewed: 01 October 2023
Next review: 01 October 2026
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.