1. What is medullary breast cancer?
2. How is medullary breast cancer diagnosed?
3. How is medullary breast cancer treated?
4. Further support

1. What is medullary breast cancer?

Medullary breast cancer is a rare type of breast cancer.

Medullary breast cancer can occur at any age but it is more often diagnosed in younger women. It is also more common in women who have inherited an altered BRCA1 gene.

It can occur in men but this is very rare.

Medullary breast cancer (sometimes referred to as carcinoma with medullary features (CMF) can be:

  • classic medullary breast cancer – when all the features of medullary breast cancer are seen under a microscope
  • atypical medullary breast cancer – when some but not all the features of medullary breast cancer are seen under a microscope
  • invasive ductal breast cancer (often called ‘no special type’ or NST) that also has some or all the features of medullary breast cancer

Medullary breast cancer is an invasive type of cancer, which means it has the potential to spread to other parts of the body, however this is not common with classic medullary breast cancer. Although each case is different, the prognosis (outlook) for classic medullary breast cancer is often good. But this may not be the case for all types of medullary breast cancer.

Medullary breast cancers are treated in the same way as other types of invasive breast cancer.

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2. How is medullary breast cancer diagnosed?

Medullary breast cancer is diagnosed using a range of tests, which may include:

  • a mammogram (breast x-ray)
  • an ultrasound scan of the breast and under the arm (axilla) – uses high frequency sound waves to produce an image
  • a core biopsy of the breast and/or lymph nodes - uses a hollow needle to take samples of breast tissue to be looked at under a microscope
  • a fine needle aspiration (FNA) of the breast and/or lymph nodes – uses a fine needle and syringe to take a sample of cells to be looked at under a microscope

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3. How is medullary breast cancer treated?

As with all types of breast cancer, the features of your medullary breast cancer will affect what treatments you might be offered.


Surgery is usually the first treatment for medullary breast cancer.

There are two main types of surgery:

The type of surgery that is recommended depends on the area of the breast affected, the size of the cancer relative to your breast and whether more than one area in the breast is affected. Your breast surgeon will discuss this with you.

Sometimes more surgery is needed if the margin of normal tissue surrounding the cancer that was removed during the first operation is not clear. This is to ensure that all the cancer has been removed. In some cases, this second operation will be a mastectomy.

If you’re going to have a mastectomy, you’ll be given the option of having breast reconstruction. This can be done at the same time as your mastectomy (immediate reconstruction) or months or years later (delayed reconstruction).

Some women decide not to have, or are unable to have, breast reconstruction. If you have a mastectomy and don’t have reconstruction you can wear an artificial breast form (prosthesis) inside your bra to restore your shape. Some women choose not to have reconstruction or wear a prosthesis.

Lymph node removal

Medullary breast cancer is less likely to spread to the lymph nodes (glands) under the arm (axilla) than other types of breast cancer. However, your specialist team will want to check if any of the lymph nodes under the arm contain cancer cells. This, along with other information about your breast cancer, helps them decide whether or not you will benefit from any additional treatment after surgery.

To do this, your surgeon is likely to recommend an operation to remove either some of the lymph nodes (a sentinel lymph node biopsy or sample) or all of them (a lymph node clearance).

Sentinel lymph node biopsy

Sentinel lymph node biopsy is widely used if tests before surgery show no evidence of the lymph nodes containing cancer cells. It identifies whether the sentinel lymph node – the first lymph node that the cancer cells are most likely to spread to – is clear of cancer cells. There may be more than one sentinel lymph node. If clear, this usually means the other nodes are clear too, so no more will need to be removed. Sentinel lymph node biopsy is usually carried out at the same time as your cancer surgery but may be done before your surgery.

If the results of the sentinel lymph node biopsy show that the first node or nodes are affected, further surgery or radiotherapy to the remaining lymph nodes may be recommended.

Sentinel lymph node biopsy is not suitable if tests carried out before your breast surgery show that your lymph nodes contain cancer cells. In this case it is likely your surgeon will recommend a lymph node clearance.

Find out more about surgery to the lymph nodes.

What are the adjuvant (additional) treatments?

After surgery, you may need other treatments. This is called adjuvant (additional) therapy and can include:

The aim of these treatments is to reduce the risk of breast cancer returning in the same breast or developing in the opposite breast, or spreading somewhere else in the body.

Some of these treatments may be given before surgery. This is known as neo-adjuvant or primary treatment.  


Chemotherapy is a treatment using anti-cancer (also called cytotoxic) drugs, which aims to destroy cancer cells. It is known as a systemic treatment as it treats the whole body.

Whether it is recommended will depend on various features of the cancer, such as its size, its grade (how quickly the cells are growing and how different they are to normal breast cells) and whether the lymph nodes are affected. It will also depend on the oestrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) status.


Radiotherapy uses high energy x-rays to destroy cancer cells. If you have breast-conserving surgery, you will usually be offered radiotherapy to the breast to reduce the risk of the cancer coming back in the same breast. Sometimes you may be offered radiotherapy to the nodes under your arm.

Radiotherapy is sometimes given to the chest wall after a mastectomy, for example if some of the lymph nodes under the arm are affected.

Hormone (endocrine) therapy

Some breast cancers are stimulated by the hormone oestrogen. This means that oestrogen in the body helps the cancer to grow. A number of hormone therapies work in different ways to block the effect of oestrogen on cancer cells.

Hormone therapy will only be prescribed if your breast cancer has receptors within the cell that bind to the hormone oestrogen, known as oestrogen receptor positive or ER+ breast cancer.

Invasive breast cancers are tested for oestrogen receptors using tissue from a biopsy or after surgery. When oestrogen binds to these receptors, it can stimulate the cancer to grow.

If oestrogen receptors are not found, the breast cancer is known as oestrogen receptor negative or ER-. Medullary breast cancer is more likely to be oestrogen receptor negative (ER-).  

Tests will also be done for progesterone (another hormone) receptors.

The benefits of hormone therapy are less clear for people whose breast cancer is only progesterone receptor positive (PR+ and ER-). Very few breast cancers fall into this category. However, if this is the case for you, your specialist will discuss whether or not hormone therapy is appropriate.

Medullary breast cancer is usually progesterone receptor negative (PR-).

If your cancer is found to be hormone receptor negative, then hormone therapy will not be of any benefit to you.

Targeted (biological) therapy

This is a group of drugs that block the growth and spread of cancer. They target and interfere with processes in the cells that cause cancer to grow.

The most widely-used targeted therapy is trastuzumab. Only people whose cancer has high levels of HER2 (called HER2 positive) will benefit from having trastuzumab. HER2 is a protein that makes cancer cells grow.

There are various tests to measure HER2 levels which are done on breast tissue removed during a biopsy or surgery. If your cancer is found to be HER2 negative, then trastuzumab or other targeted therapies for people with HER2 positive breast cancer will not be of any benefit.

Medullary breast cancer is usually HER2 negative.


Bisphosphonates are a group of drugs that can reduce the risk of breast cancer spreading in postmenopausal women. They can be used regardless of whether the menopause happened naturally or because of breast cancer treatment.

Bisphosphonates can also slow down or prevent bone damage. They’re often given to people who have, or are at risk of, osteoporosis (when bones lose their strength and become more likely to break).

Bisphosphonates can be given as a tablet (orally) or into a vein (intravenously).

Your specialist team can tell you if bisphosphonate treatment would be suitable for you.

Triple negative breast cancers

When breast cancers are HER2 negative, oestrogen receptor negative and progesterone receptor negative, this is referred to as ‘triple negative’ breast cancer. This is quite common in medullary breast cancer. If you have triple negative breast cancer, you may feel concerned that you are not able to have treatments such as trastuzumab or hormone therapy. However, people diagnosed with medullary breast cancer generally have a better prognosis (outlook) than people with some other types of triple negative breast cancer.

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4. Further support

Being diagnosed with breast cancer can make you feel lonely and isolated.

Many people find it helps to talk to someone who has been through a similar experience as them. Breast Cancer Now’s Someone Like Me service can put you in touch with someone who has had a diagnosis of breast cancer, so you can talk through your worries and share experiences over the phone or by email. You can also visit our confidential online Forum and join one of the ongoing discussions.

If you would like any further information and support about breast cancer or just want to talk things through, you can speak to one of our experts by calling our free Helpline on 0808 800 6000.

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Last reviewed: August 2018
Next planned review begins underway

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