1. What is invasive lobular breast cancer?
2. What are the symptoms of invasive lobular breast cancer?
3. How is invasive lobular breast cancer diagnosed?
4. How is invasive lobular breast cancer treated?
5. What are the adjuvant (additional) treatments for invasive lobular breast cancer?
6. Follow-up after treatment
7. Further support

1. What is invasive lobular breast cancer?

Invasive lobular breast cancer is a type of breast cancer that starts in the lobules (milk-producing glands) of the breast. It accounts for up to 15% of all breast cancers.

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

Invasive lobular breast cancer occurs when these abnormal cancer cells have started to grow within the lobules and then spread into the surrounding breast tissue.

Lobules diagram

Invasive lobular breast cancer can occur at any age but is most common in pre-menopausal women (women who have not been through the menopause). Men can also get invasive lobular breast cancer but this is very rare. Find out more about breast cancer in men.

Sometimes invasive lobular breast cancer is found mixed with other types of breast cancer such as DCIS (ductal carcinoma in situ) or invasive ductal breast cancer.

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2. What are the symptoms of invasive lobular breast cancer?

Possible symptoms of invasive lobular breast cancer include:

  • an area that feels thicker or harder than the rest of the breast
  • changes in skin texture such as puckering or dimpling (like the skin of an orange)
  • the nipple becoming pulled in

Invasive lobular breast cancer may not cause any obvious changes to the breast, like a definite lump.

In some women it is found during routine breast screening before any symptoms are noticed, but lobular breast cancer can be more difficult to see on a mammogram than other types of breast cancer.

Find out more about the signs and symptoms of breast cancer and how to check your breasts.

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3. How is invasive lobular breast cancer diagnosed?

Invasive lobular breast cancer can be difficult to diagnose if there are no obvious symptoms.

When you visit the breast clinic you will usually have:

A small sample of breast cells or breast tissue may be taken from the breast to help make a diagnosis. This will most commonly be done using a core biopsy. Sometimes a fine needle aspiration (FNA) may be used. The sample is then sent to the laboratory where it is looked at under a microscope.

Invasive lobular breast cancer can sometimes be more difficult than other types of breast cancer to locate and measure using an ultrasound or mammogram, so you may have a magnetic resonance imaging (MRI) scan. An MRI uses magnetism and radio waves to produce a series of images of the inside of the body. It doesn’t expose the body to x-ray radiation. It can sometimes provide a more accurate picture of the size of this type of cancer, and whether it affects more than one area in the breast. Both breasts will be checked.

Find out more about the tests you may have at the breast clinic and getting your results.   

Sometimes more than one area of invasive lobular cancer is found in the same breast.

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4. How is invasive lobular breast cancer treated?


Surgery is usually the first treatment for invasive lobular breast cancer.

The type of surgery recommended will depend on the area of the breast affected, the size of the cancer compared to the size of your breast, and whether more than one area in the breast is affected.

Breast-conserving surgery

Breast-conserving surgery, also known as wide local excision or lumpectomy, is the removal of the cancer with a margin (border) of normal breast tissue around it.

If breast-conserving surgery is being considered, an MRI scan may be recommended to assess the size of the cancer (if you haven’t already had one to confirm the diagnosis). Your breast surgeon will discuss this with you.

Even after an MRI scan, it can sometimes be difficult to estimate the size of an invasive lobular breast cancer before surgery. Because of this, some women who have breast-conserving surgery may need a second operation. This is to ensure all the cancer, and a margin of normal breast tissue around it, has been removed. In some cases, a mastectomy will be recommended as the second operation.


A mastectomy is the removal of all the breast tissue and nipple area.

Invasive lobular breast cancer can affect more than one area in the breast. If this is the case the breast surgeon may recommend a mastectomy, but this will depend on the position of the areas affected and the size of your breast.

If a mastectomy is recommended, or if you choose to have a mastectomy, you will usually be able to have breast reconstruction. This can be done at the same time as your mastectomy (immediate reconstruction) or sometime in the future (delayed reconstruction).

Surgery to the lymph nodes

Your doctors will also want to check whether breast cancer cells have spread from the breast to the lymph nodes (glands) under the arm (axilla). This will help them decide whether you will need additional treatment after surgery. To do this, your surgeon is likely to recommend an operation to remove either some of the lymph nodes (a lymph node sample or biopsy) or all of them (a lymph node clearance).

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 first lymph node (or nodes) is clear of cancer cells. If it is, this usually means the other nodes are also clear, so no more will need to be removed.

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

Find out more about surgery to the lymph nodes.

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5. What are the adjuvant (additional) treatments for invasive lobular breast cancer?

After surgery you may need further treatment. This is called adjuvant (additional) therapy and includes:

Which treatment you have will depend on your individual situation.

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

Sometimes chemotherapy or hormone therapy may be given before surgery. This is known as neo-adjuvant or primary therapy.


If you have breast-conserving surgery you will usually be given radiotherapy to reduce the risk of the breast cancer returning in the same breast (known as recurrence). Sometimes you may be offered radiotherapy to the nodes under your arm.

If you have a mastectomy you may be given radiotherapy to the chest in the area where you had your surgery. This is more likely if the tumour was large, if there is a high risk that cancer cells may have been left behind or if cancer cells are found in the lymph nodes under the arm (axilla).

Hormone (endocrine) therapy

As the hormone oestrogen can play a part in stimulating some breast cancers to grow, there are a number of hormone therapies that 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). All breast cancers are tested for oestrogen receptors using tissue from a biopsy or after surgery.


Chemotherapy is recommended for some people. This will depend on various features of the cancer, such as its size, its grade (how different the cells are to normal breast cells and how quickly they are growing) and whether the lymph nodes are affected.

Targeted 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 (Herceptin). 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. Most invasive lobular breast cancers are HER2 negative.

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6. Follow-up after treatment

You will continue to be monitored after your hospital-based treatments (such as surgery, chemotherapy or radiotherapy) finish. This is known as follow-up.

Having breast cancer in one breast means the risk of developing cancer in the other breast (a new primary breast cancer) is slightly higher than in someone who’s never had breast cancer. With invasive lobular breast cancer, this risk may be slightly higher than with other types of breast cancer, but it’s still very low overall.

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7. Further support

Being diagnosed with breast cancer can be a difficult and frightening time.

There may be times when you feel alone or isolated. There are people who can support you so don’t be afraid to ask for help if you need it.

Some people find it helpful to discuss their feelings and concerns with their breast care nurse or specialist. If you’d like to talk through your feelings and concerns in more depth over a period of time, you may want to see a counsellor or psychologist. Your breast care nurse, specialist or GP can arrange this.

You may find our information on coping emotionally helpful.

You can also call Breast Cancer Now’s Helpline on 0808 800 6000 and talk through your diagnosis, treatment and how you are feeling with one of our team.   

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Last reviewed: January 2018
Next planned review begins 2019

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