Types of breast cancer

There are different types of breast cancer. Knowing the type you have allows your doctor to plan the best treatment for you.

Ductal carcinoma in situ (DCIS) is the earliest form of breast cancer. DCIS is when there are cancer cells in the ducts of the breast. But these cells are contained (in situ) and have not spread into normal breast tissue. DCIS may show on a mammogram and is usually diagnosed when women have a breast screening.

Lobular carcinoma in situ (LCIS) is not breast cancer, although it’s name can be misleading. There are changes in the cells lining the lobes that show a woman has an increased risk of developing breast cancer later in life. But most women with LCIS don’t get breast cancer. They have regular check-ups with breast examinations and mammograms.

Invasive breast cancer

Invasive breast cancer means the cancer cells have spread outside the lining of the ducts or lobes into the surrounding breast tissue.

Invasive ductal breast cancer

Most invasive breast cancers (80%) start in the ducts of the breast.

Invasive lobular breast cancer

About 1 in 10 invasive breast cancers (10%) start in the lobes of the breast. This type can sometimes be difficult to diagnose on a mammogram because of the way it grows. Some women may need an MRI scan.

Doctors test the cancer cells to decide which treatments are best for you. They look at whether the cells have receptors (proteins) for hormones like oestrogen or a protein called HER2 (HER2 positive breast cancer).

Breast cancer that has no receptors is called triple negative breast cancer.

Uncommon types of breast cancer

Inflammatory breast cancer

This is when cancer cells grow along and block the tiny channels (lymph vessels) in the skin of the breast. The breast then becomes inflamed and swollen.

Paget’s disease of the breast

This shows as a red, scaly rash (like eczema) on the skin of the nipple. Women with Paget’s disease may have DCIS or invasive breast cancer.

We have more information about different types of breast cancer, including malignant phyllodes tumour. If you have a type of breast cancer we haven't mentioned here, call the Macmillan Support Line on 0808 808 00 00.

Back to Understanding breast cancer

What is cancer?

There are more than 200 different kinds of cancer, each with its own name and treatment.

Cancer and cell types

Cancers are grouped into types. Types of cancer often behave and respond to treatments in different ways.

The breasts

Breasts are made of fat, supportive (connective tissue) and glandular tissue that contains lobes (milk glands).

Why do cancers come back?

Sometimes, tiny cancer cells are left behind after cancer treatment. These can divide to form a new tumour.