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 tumour is seen in the breast or the tumour may be any size and cancer is found in 4 to 9 lymph glands under the arm or in the lymph glands near the breastbone

• the tumour is larger than 5cm and small clusters of breast cancer cells are in the lymph nodes

• the tumour is more than 5cm and has spread into up to 3 lymph nodes in the armpit or to the lymph nodes near the breastbone

Stage 3B

Stage 3B means the tumour 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 tumour can be any size, or there may be no tumour. But there is cancer in the skin of the breast, causing swelling or an ulcer and it has spread to the chest wall. It has also spread to one or more of the following structures:

• 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

For treatment, doctors divide stage 3C breast cancer into cancers that can be operated on (operable breast cancers) and those that can't (inoperable cancer).

TNM stages

The TNM staging system stands for Tumour, Node, Metastasis.

• T describes the size of the tumour (cancer)
• N describes whether there are any cancer cells in the lymph nodes
• M describes whether the cancer has spread to a different part of the body

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 a 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 targeted cancer drug called trastuzumab (Herceptin).

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). You may then be able to have a new breast made (breast reconstruction). 

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