Stage 3 means that the cancer has spread from the breast to lymph nodes close to the breast or 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 which treatment you need.
Staging for breast cancer is very complex. Many different factors are considered before doctors can confirm your final stage. For example, they also use a sample of your cancer to test for:
- receptors for the female hormones
- HER2 status (human epidermal growth factor receptor 2)
- the grade of your cancer
You may also have a CT scan to check that the cancer has not spread to other parts of your body.
Do speak to your breast doctor or nurse if you have any questions about staging.
What is stage 3 breast cancer?
Stage 3 breast cancer is divided into 3 groups.
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 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 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).
The TNM staging system stands for Tumour, Node, Metastasis.
- T describes the size of the tumour
- 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
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 more drug treatments.
Or you might have surgery as a first treatment followed by chemotherapy or other drug treatments.
Drug treatment before surgery
You might have chemotherapy as a first treatment to shrink the cancer down.
You might have hormone therapy first if your cancer cells have hormone receptors. But you usually only have this if chemotherapy isn’t suitable.
If your cancer cells have particular proteins called HER2 receptors you might also have a targeted cancer drug called trastuzumab (Herceptin).
These treatments might shrink the tumour enough to allow your surgeon to remove just the area of 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 be able to have a new breast made (breast reconstruction). Do speak to your surgeon about this.
Before your surgery the lymph nodes in the armpit are checked for cancer cells.
You usually have radiotherapy to the breast after surgery.
Surgery as a first treatment
You may have the whole breast removed (a mastectomy). You may be able to have a new breast made (breast reconstruction). Do speak to your surgeon, they will tell you whether a reconstruction is suitable for you.
You might be able to have breast conserving surgery. This may be possible if you have drug treatment first and the tumour shrinks enough to allow your surgeon to remove just the area of cancer. Before your surgery the lymph nodes in the armpit are checked for cancer cells.
After the surgery you usually have radiotherapy to the breast area.
You might have treatment with chemotherapy for a few months. If your cancer cells have receptors for a protein called HER2 you might have a targeted cancer drug called trastuzumab (Herceptin) as well as chemotherapy. You may have this for up to a year.
You usually have hormone therapy for at least 5 years if your cancer cells have hormone receptors.
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
Bone strengthening treatment
You may also have treatment with a group of drugs that strengthen the bones. These are called bisphosphonates. For some people this treatment can help reduce the risk of their breast cancer spreading to the bones. You may have this if you have locally advanced breast cancer and no longer have periods (post menopausal).
Inflammatory breast cancer
Some stage 3 cancers are a type called inflammatory breast cancers. The treatment is slightly different than for other stage 3 breast cancers.