What is triple negative breast cancer?

Triple negative breast cancer is a less common type of breast cancer. About 1 in 5 breast cancers are triple negative (15 to 20%). 

Breast cancer cells may have receptors for hormones and proteins. These hormones and proteins encourage the cancer cells to grow. The breast cancer surgeon takes a sample of cancer cells during a biopsy or surgery. They test the sample for these receptors. If receptors are found, you are usually treated with hormonal therapy or targeted therapy.

Breast cancer is called triple negative when it does not have receptors for these hormones or for the HER2 protein. This means treatments such as hormonal therapy or HER2 targeted therapy are not suitable for people with triple negative breast cancer.

Treatment for triple negative breast cancer includes: 

Research is going on to find new treatment options.

Triple negative breast cancer is sometimes described as a faster-growing type of breast cancer. This may make you feel worried about it coming back. But the risk of it coming back depends on the same factors as any other type of breast cancer

Basal cell breast cancer

Basal cell is a type of breast cancer. Changes in proteins in the cells can be seen when cancer cells are examined under a microscope. Basal cell breast cancers are usually triple negative.

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Symptoms of triple negative breast cancer

The symptoms of triple negative breast cancer are the same as for other breast cancer types.

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Causes of triple negative breast cancer

Triple negative breast cancer is more common in women under 40. It is more common in Black women. But triple negative breast cancer can develop at any age and in any ethnicity. Triple negative breast cancer is rare in men.

The risk factors for triple negative breast cancer are not clear. Some breast cancers depend on hormones to grow. These breast cancers can be linked to risk factors related to hormones and having children. But triple negative breast cancer does not seem to share these risk factors.

Most women with triple negative breast cancer have no strong history of breast cancer in their family (inherited breast cancer). But some women with triple negative breast cancer have an inherited gene change. This is called a gene variant. Around 1 in 5 triple negative breast cancers (15%) are caused by inherited gene variants. The most common is BRCA1 gene. Another type is BRCA2. Research is looking into other types of gene variant. We have more information about gene variants and breast cancer.

If you have triple negative breast cancer, you may be offered genetic testing. This is even if you do not have a family history of breast cancer. Your cancer doctor or breast care nurse can explain more about this to you.

We have more information about the risk factors and causes of breast cancer.

Diagnosis of triple negative breast cancer

The tests are the same as for any type of breast cancer. You usually have a:

  • Mammogram

    A mammogram is an x-ray of the breast.

  • Ultrasound scan

    An ultrasound scan scan uses sound waves to produce a picture of the breast tissue and the lymph nodes (glands) in the armpit.

  • Breast biopsy

    When you have a breast biopsy, your cancer doctor or breast care nurse takes small samples of cells or tissue from your breast. The samples are looked at under a microscope to check for cancer cells. They are also tested to find out whether the cells have receptors (proteins) for hormones or for HER2.

Staging and grading of triple negative breast cancer

The staging and grading is the same as for other types of breast cancer:

Stage

The stage of a cancer describes its size and how far it has spread. Knowing this helps your cancer doctor plan the best treatment for you.

Grade

The grade describes how the cancer cells look under a microscope. It gives an idea of how quickly the cancer may develop. There are 3 grades of breast cancer. They range from grade 1 (low grade) to grade 3 (high grade). Triple negative is more likely to be high grade.

Learn more about the staging and grading of breast cancer.

Treatment for triple negative breast cancer

Your cancer doctor will talk to you about the best treatment for you. This depends on different factors, such as the stage and grade of the cancer. It also depends on whether you have any other health problems.

Treatment for triple negative breast cancer is usually a combination of:

You may have chemotherapy as your first treatment before surgery to remove the cancer. You may also have other treatments such as targeted therapy or immunotherapy.

Always tell your cancer doctor or breast care nurse about any treatment side effects you have. There are usually ways to control side effects. Your cancer doctor or breast care nurse will tell you about ways to help manage them.

Some treatments for breast cancer can affect whether you are able to start a pregnancy (your fertility). If this is important to you, talk to your doctor or nurse before you start your treatment. They can talk about how it may affect you and what your options are. There are drugs and other ways of preserving your fertility.

Surgery

The type of surgery you have depends on:

  • the size and position of the cancer
  • your preference.

You and your breast surgeon will decide which operation is best for you. You may be asked to choose which operation you want to have.

  • Breast-conserving surgery

    The surgeon removes the cancer and some normal-looking tissue around it (a clear margin). This is called a wide local excision (WLE) or sometimes a lumpectomy. You usually have radiotherapy after a WLE. This is to treat any remaining cancer cells.
    Mastectomy

  • Mastectomy

    In some cases, the surgeon may advise a mastectomy. This is when the whole breast is removed. This may be because the cancer is large compared to the rest of the breast. Or it may be because there are several areas of cancer, in different parts of the breast.

Your surgeon will explain more about the type of surgery that is suitable for you. Some people choose to have a mastectomy instead of a WLE.

Breast reconstruction

If you are having a mastectomy, your surgeon may ask if you want a new breast shape made during the operation. This is called an immediate breast reconstruction. You can also choose to delay reconstruction until after your treatment.

Breast reconstruction is specialised surgery done by expert surgeons. There are different types of reconstruction available. Your cancer doctor or breast care nurse will talk to you about this.

Surgery to the lymph nodes

Your surgeon may remove some or all the lymph nodes in your armpit to check them for cancer cells. This can also:

  • remove any lymph nodes that contain cancer cells
  • give your doctor information about the stage of the cancer.

There are different types of lymph node biopsy. You may need more treatment if only some lymph nodes were removed.

Chemotherapy

Chemotherapy is an important treatment for triple negative breast cancer. This is because it is usually more effective against cancer cells that are faster growing (high grade). But you are usually offered chemotherapy even if triple negative breast cancer is low grade or has not spread to the lymph nodes in the armpit.

For breast cancer, you usually have chemotherapy after surgery. This is called adjuvant chemotherapy. You have it to reduce the chance of the cancer coming back. But you can have chemotherapy before surgery. This is called neo-adjuvant chemotherapy. If you have triple negative breast cancer, you are more likely to have chemotherapy before surgery.

Chemotherapy can cause side effects, but many of these can be well controlled. Side effects usually improve after treatment has finished.

Chemotherapy drugs

Triple negative breast cancer usually responds well to chemotherapy. Clinical trials try to find out more about the most effective drugs to use.

The chemotherapy drugs used to treat triple negative breast cancer include doxorubicin or epirubicin. You usually have 1 of these with docetaxel or paclitaxel. Your cancer doctor or breast care nurse will explain about the drugs that may be suitable for you. 

Carboplatin is also commonly used to treat triple negative breast cancer. It is often used in people with BRCA gene variants.

Capecitabine is sometimes used to treat triple negative breast cancer. A newer drug called nab-paclitaxel is also now being used. It is usually given with atezolizumab for triple negative breast cancer that has spread (metastatic).

Radiotherapy

Radiotherapy treats cancer using high-energy x-rays to destroy the cancer cells, while doing as little harm as possible to normal cells. You usually have it after surgery and chemotherapy.

If you have had breast-conserving surgery, you will have radiotherapy to the remaining breast tissue. This reduces the risk of the cancer coming back in that area. If you have had a mastectomy, sometimes you may have radiotherapy to the chest area.

You usually have radiotherapy as a series of short daily treatments. Each treatment is called a fraction or a session. You usually have 5 sessions of radiotherapy over 1 week. Sometimes it is given as 15 sessions over 3 weeks. Your cancer doctor or nurse will tell you how many sessions you will need.

Radiotherapy to the breast can cause some side effects. These are usually mild. Your cancer doctor, nurse or radiographer will talk to you about how to manage these.

Immunotherapy

Immunotherapy drugs help the immune system recognise and destroy cancer cells. You usually have immunotherapy drugs as a drip into a vein (intravenously).

You may have the immunotherapy drug pembrolizumab (Keytruda®) for early triple negative breast cancer. You may be offered this treatment with chemotherapy before surgery. This is called neo-adjuvant chemotherapy. You usually continue to have pembrolizumab on its own after surgery.

Atezolizumab (Tecentriq®) is another immunotherapy drug you may have with chemotherapy. This is usually given for triple negative breast cancer that has spread (metastatic). Your cancer doctor may arrange tests on the cancer cells that were removed to check if this treatment is likely to work for you.

Your cancer doctor or nurse can tell you more about whether immunotherapy is suitable for you.

Targeted therapy

Targeted therapy drugs interfere with the way cancer cells grow.

Olaparib (Lynparza®) is a targeted drug that can work in cancer cells that have a change (mutation) in the BRCA gene.

Sacituzumab govitecan is a new targeted drug. It may be used to treat triple negative breast cancer that has spread (metastatic).

Clinical trials

Your cancer doctor may talk to you about having treatment as part of a clinical trial. Clinical trials test new treatments or different combinations of treatment. This may include testing different combinations of chemotherapy, targeted and immunotherapy drugs, or anti-androgen drugs.

Anti-androgen drugs

Androgens are hormones made in your body. Some triple negative breast cancers have androgen receptors on the surface of the cancer cells. These are called androgen positive.

Enzalutamide is an anti-androgen drug that has been used in a clinical trial for triple negative breast cancer. Your cancer doctor or nurse can tell you more about this.

After triple negative breast cancer treatment

After treatment, you usually have regular follow-up appointments for a few years. These usually include a mammogram. We have more information about follow-up after breast cancer.

Your appointments are a good opportunity to talk about any concerns you have. If you notice new symptoms between appointments, it is important to contact your cancer doctor or breast care nurse.

Being diagnosed with cancer, and having treatment, may cause lots of different emotions. 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:

There are also other organisations and charities that support people with triple negative breast cancer. This includes Breast Cancer Now and the UK Charity for Triple Negative Breast Cancer.

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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, Dr Rebecca Roylance, Consultant Medical Oncologist.

    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.

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

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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.

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Date reviewed

Reviewed: 01 October 2023
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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.

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