Stage 4 breast cancer
The stage of a cancer tells you how big it is and whether it has spread. It helps your doctor decide which treatment you need.
Stage 4 breast cancer has spread to another part of the body. It is also called advanced cancer or secondary breast cancer. The aim of treatment is to control the cancer and any symptoms. Treatment depends on a number of factors.
There are different systems used in the UK to stage breast cancer. Stage 4 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. Below is a simplified description of stage 4 breast cancer.
In stage 4 breast cancer:
- the cancer can be any size
- the
lymph nodes 
may or may not contain cancer cells - the cancer has spread (metastasised) to other parts of the body such as the bones, lungs, liver or brain
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 4 breast cancer is the same as:
- Any T Any N M1
Treatment
Your doctor will take many different factors into account when deciding which treatment is best for you. These include:
- the type of cells the cancer started in
- which part of your body the cancer has spread to
- the treatment you have already had
- your general health
- whether you have had the
menopause - whether the cancer is growing slowly or more quickly
- whether the cancer cells have receptors for particular cancer drugs
Secondary breast cancer may respond to several types of treatment. Doctors usually start with treatment that has as few side effects as possible.
Stage 4 breast cancer is unlikely to be cured. But treatment can often keep the cancer under control for many months or years.
Hormone therapy
Hormone therapy is a common treatment for secondary breast cancer. It can often shrink and control the cancer wherever it is in the body. It works well if the cancer cells have particular proteins called hormone receptors.
If one hormone therapy stops working so well, your doctor might suggest you try a different one.
Chemotherapy
Your doctor might suggest chemotherapy if your cancer doesn't have hormone receptors or has spread to the liver or lungs.
Targeted and immunotherapy drugs
There are different types of targeted and immunotherapy drugs for secondary breast cancer. They include trastuzumab (Herceptin) and palbociclib.
Radiotherapy
You might have radiotherapy if the cancer has spread to the bones or the skin near the breast.
Other treatments you might have
You may have other treatments too. These include:
- drugs that strengthen the bones called bisphosphonates
- medicines to control symptoms that the cancer causes
- surgery to help to relieve symptoms
