Stages of invasive breast cancer

Early breast cancer

Early breast cancer is invasive cancer that is contained in the breast. It may or may not have spread to lymph nodes in the breast or armpit. Some cancer cells may have spread outside the breast and armpit area but cannot be detected.

Early breast cancer is sometimes called Stage 1 or Stage 2 breast cancer.^[11]

Locally advanced breast cancer

Locally advanced breast cancer is invasive breast cancer that:

is large – often bigger than 5 cm
might have spread to several lymph nodes in the armpit (axillary lymph nodes) or other areas near the breast
might have spread to other tissues around the breast – such as the skin, muscle or ribs – but not beyond.

Locally advanced breast cancer is generally Stage 3 breast cancer, but can sometimes be Stage 2.^[12] It is not the same as metastatic breast cancer, which occurs where breast cancer has spread to other, more distant parts of the body. ^[13]

About 10% to 20% of all the breast cancers diagnosed in Australia each year are locally advanced breast cancer.^[14]

Read about the symptoms and diagnosis of breast cancer.

Metastatic breast cancer

Metastatic (or advanced or Stage 4) breast cancer is invasive breast cancer that has spread from the breast to other parts of the body through the bloodstream or lymphatic system to form a new cancer (metastasis).

It often spreads to the bones, liver, lung or brain, though not necessarily to all these places.

Many women diagnosed with metastatic breast cancer have previously been diagnosed with breast cancer (called recurrent cancer). But a diagnosis of metastatic breast cancer can be their first cancer diagnosis.

Subtypes of breast cancer^[15] ^[16]

Breast cancers are also classified by their receptor status. Receptors are the proteins on the cells that signal a specific response in the body. Cancer cells have unique receptors that promote their growth and survival. In breast cancer, there are 3 main types of receptors:

Oestrogen receptors

Progesterone receptors

HER-2 receptors

Hormone receptor positive breast cancer 

When breast cancer cells have hormone receptors on them (hormone receptor positive), it means they need female hormones (oestrogen and/or progesterone) to grow and reproduce.

There are 2 types of hormone receptors – oestrogen receptors and progesterone receptors. Hormonal therapies or endocrine therapies reduce the ability of hormones to bind to hormone-receptor positive breast cancer cells, and slow their growth.

About 3 in 4 breast cancers are hormone receptor positive.^[17]

HER2-positive breast cancer 

Human epidermal growth receptor 2 (HER2) is a protein that helps cells to grow and divide. HER2-positive breast cancer cells have too much of the protein HER2. These receptors promote the growth of the cancer cells.

About 1 in 5 of breast cancers are HER2 positive.^[18] 

HER2-positive breast cancer is a more aggressive form of breast cancer than HER2-negative cancer. The pathology report shows whether a woman’s breast cancer cells are HER2 positive.

Targeted therapies are used to treat HER2-positive breast cancers.

Triple negative breast cancer 

Triple negative breast cancer does not have any of the 3 receptors commonly found on breast cancer cells (oestrogen, progesterone and HER2). About 15% of breast cancers are triple negative^[19].

These are normally treated with a combination of chemotherapy, surgery and/or radiotherapy.

Some people are more likely to get breast cancer than others. Read about risk factors for breast cancer.