What is lobular carcinoma in situ (LCIS)?

The breast contains lobes where milk is made. LCIS is a condition where there are abnormal changes in the cells that line the lobes. LCIS is also called lobular neoplasia.

LCIS is not a cancer. The abnormal changes mean that a woman has a higher than average risk of developing breast cancer later in life.

Even if LCIS is only diagnosed in the left or right breast, the risk of developing cancer is similar in both breasts. Some women have LCIS in both breasts. But most women with LCIS do not develop breast cancer.

LCIS is more common in women who have not been through the menopause. It is more common in women aged between 40 and 50.

Side view of the breast

Diagnosing LCIS

There are no symptoms for LCIS, and it does not show up on a mammogram (breast x-ray). So it is usually found by chance.

This could be when a sample of breast tissue is taken (biopsy), or if a breast lump is removed for another reason. Because of this, LCIS is often not found. It usually does not cause any problems.

If LCIS is diagnosed after a needle or vacuum-assisted biopsy, you may need more tissue removed. This is a small operation called an excision biopsy. It is usually done to make sure there are no cancer cells in the area. The surgeon removes the tissue under a general or local anaesthetic. You can usually have this done as day surgery and may go home on the same day. The tissue is then looked at under a microscope.

Managing LCIS

If you have LCIS, you will not need any treatment. Most women with LCIS do not develop breast cancer, so they never need treatment. You will be offered regular monitoring. This is to make sure that if a cancer does develop, it is found early.

If this happens, you can start breast cancer treatment straight away. Treatment for early breast cancer is usually very successful. Your specialist doctor and nurse will explain how you will be followed up after your treatment.

There is a rare type of LCIS called pleomorphic LCIS. It is usually treated in a similar way to ductal carcinoma in situ (DCIS). If you are diagnosed with this type of LCIS, your cancer doctor and specialist nurse will explain more about it.

Monitoring or screening

Doctors usually recommend women with LCIS have mammograms every 1 to 2 years. You may also be offered MRI scans.

Even though you are being monitored, it is still important to know how your breasts look and feel at different times of the month. This means you will know what is normal for you.

Changes to look for include:

  • a lump in the breast
  • a change in the size or shape of the breast
  • the skin of your breast feeling thicker
  • a nipple that is turned in (inverted)
  • a rash (like eczema) on the nipple or breast
  • leaking (discharge) from the nipple
  • swelling or a lump in the armpit
  • discomfort or pain in the breast that does not go away.

If you notice any changes, tell your doctor or specialist nurse as soon as possible. The changes could be for many reasons other than cancer.

Lowering the risk of breast cancer

Some hormonal therapy drugs can reduce the risk of breast cancer developing in women with LCIS. Your doctor or specialist nurse may talk to you about taking a hormonal therapy if it is an option for you. It is not clear how much the reduction in risk outweighs the side effects of hormonal therapy drugs.

You might have a pattern of breast cancer in your family. For example, there may be a number of family members who have been diagnosed with breast cancer. If this is the case, you may be referred to a genetics clinic to see a specialist. At the clinic, you have a risk assessment and genetic counselling.

Some women who are assessed as having a high risk of breast cancer, may think about having surgery to remove both breasts removed. This is to reduce the risk of breast cancer developing. It is called risk-reducing breast surgery.

Talk to your doctor or specialist nurse if you are worried about your family history or risk of developing breast cancer.

Your feelings about LCIS

It is natural to feel worried if you know that your risk of developing breast cancer is increased. But LCIS is not a cancer, and most women with it will never develop breast cancer.

It can be reassuring to know that you will have regular checks and support from your specialist doctor and nurse. Talk to them about any concerns you have. You can also talk to one of our cancer support specialists on 0808 808 00 00.