Stage 3 breast cancer

Stage 3 means that the cancer has spread from the breast to the lymph nodes close to the breast, to the skin of the breast or to the chest wall. It is also called locally advanced breast cancer.

The stage of a cancer tells you how big it is and how far it has spread. It helps your doctor decide the best treatment for you. There are different systems used in the UK to stage breast cancer. Stage 3 is part of the number staging system. Doctors may also use the TNM staging system.  

Staging for breast cancer is very complex. Many different factors are considered before doctors can confirm your final stage. Speak to your doctor or breast cancer nurse specialist if you have any questions about your staging.

Stage 3 can be divided into 3A, 3B and 3C. Below is a simplified description of stage 3A, 3B and 3C breast cancer. 

Stage 3A

Stage 3A means one of the following:

• no cancer is seen in the breast or the cancer is of any size within the breast. And there is cancer in 4 to 9 lymph nodes under the arm or in lymph nodes near the breastbone

• the cancer is larger than 5 cm and has spread to 1 to 3 lymph nodes under the arm or to the lymph nodes near the breastbone

Stage 3B

Stage 3B means the cancer has spread to the skin of the breast or the chest wall. The chest wall means the structures surrounding and protecting the lungs, such as the ribs, muscles, skin or connective tissues. The cancer has made the skin break down (an ulcer) or caused swelling. The cancer may have spread to up to 9 lymph nodes in the armpit or to the lymph nodes near the breastbone.

Cancer that has spread to the skin of the breast might be an inflammatory breast cancer.

Stage 3C

Stage 3C means the cancer can be any size, or there may be no cancer seen in the breast. The cancer may have grown into the chest wall or skin of the breast. The cancer has spread to one of the following:

• 10 or more lymph nodes in the armpit

• lymph nodes above or below the collar bone

• lymph nodes in the armpit and near the breastbone

TNM stages

TNM stands for Tumour (T), Node (N) and Metastasis (M). The staging is different depending on the type of cancer you have.

The information below is an overview of the TNM staging for all types of cancer.

• T describes the size of the tumour (cancer)
• N describes whether there are any cancer cells in the nearby lymph nodes
• M describes whether the cancer has spread to parts of the body further away from where the cancer started

The doctor gives each factor (T, N and M) a number. The number depends on how far the cancer has grown or spread.

So, a very small cancer which hasn't spread to the lymph nodes or elsewhere in the body may be T1 N0 M0.

A larger cancer that has spread into the nearby lymph nodes and to another part of the body may be T3 N1 M1.

In the TNM staging system, stage 3A breast cancer is the same as:

• T0 N2 M0
• T1 N2 M0
• T2 N2 M0
• T3 N1 M0
• T3 N2 M0

Stage 3B is the same as:

• T4 N0 M0
• T4 N1 M0
• T4 N2 M0

Stage 3C is the same as:

• Any T N3 M0

Treatment

The number staging helps your doctor decide which treatment you need. Treatment also depends on:

• the type of cells the cancer started in
• whether your cancer cells have receptors for particular cancer drugs
• the grade of the cancer 
• whether you have had the menopause    
• other health conditions you may have

Your doctor will take many different factors into account when deciding which treatment is best for you.

You might have drug treatments such as chemotherapy with or without a targeted cancer drug as a first treatment. This is followed by surgery and then radiotherapy or more drug treatments. 

Or you might have surgery as a first treatment followed by radiotherapy, chemotherapy or other drug treatments.

Drug treatments before surgery

You might have chemotherapy as the first treatment to shrink the cancer.

Or you might have hormone therapy first if your cancer cells have hormone receptors  and it's not suitable for chemotherapy. If your cancer cells have HER2 receptors, you might also have a combination of trastuzumab (Herceptin), pertuzumab and chemotherapy.

These treatments might shrink the cancer enough to allow your surgeon to remove just the area of the cancer. This is called breast conserving surgery or a wide local excision.

If the cancer doesn’t shrink enough, you need to have the whole breast removed (mastectomy). 

Surgery

You might have breast conserving surgery or a mastectomy. After a mastectomy, you may be able to have a breast reconstruction. Do speak to your surgeon, they will tell you whether a reconstruction is suitable for you. 

After the surgery, you usually have more treatment. This includes:

• radiotherapy
• chemotherapy
• targeted cancer drugs
• hormone therapy 
• drugs that strengthen the bones called bisphosphonates 

Checking the lymph nodes

Before your treatment, you have an ultrasound scan to check the lymph nodes in the armpit (axilla) close to the breast. This is to see if they contain cancer cells. If breast cancer spreads, it usually first spreads to the lymph nodes close to the breast.

Depending on the results of your scan you might have:

• a sentinel lymph node biopsy during your breast cancer operation
• surgery to remove your lymph nodes

Other stages of breast cancer