Brain Metastases in Breast Cancer: Symptoms, Diagnosis and Treatment

What are brain metastases?

Brain metastases, sometimes called secondary or metastatic breast cancer in the brain, or 'brain mets', happen when breast cancer cells spread from the breast to the brain. The cancer in the brain is still breast cancer, made of breast cancer cells. It is not a new, separate brain tumour, and it is treated as breast cancer.

For most people, the breast cancer has already spread to another part of the body, such as the bones, liver or lungs, before or at the same time as it reaches the brain. For some people, the brain is the only place the cancer has spread to. This is also called advanced, secondary or stage 4 breast cancer.

Like other forms of secondary breast cancer, the NHS explains that secondary cancer in the brain cannot usually be cured. But treatment can often control the cancer, ease symptoms and help you feel better. The aim is to relieve symptoms, slow the cancer down and help you live as well as possible for as long as possible.

This page is general information, not personal medical advice. Everyone's situation is different. Your oncologist, breast care nurse and GP know your own circumstances, so please always check with your treatment team about what is right for you.

Symptoms to look out for

The symptoms of breast cancer in the brain depend on which part of the brain is affected and how much swelling there is around it. Some symptoms come on gradually, while others appear more suddenly. According to Breast Cancer Now, common symptoms can include:

• Headaches, which may be worse in the morning or when you cough, bend or strain.
• Feeling sick (nausea) or being sick (vomiting).
• Weakness or numbness down one side of the body, or in an arm or leg.
• Unsteadiness, or loss of balance and coordination.
• Seizures (fits).
• Difficulty with speech.
• Problems with vision, such as blurred or double vision.
• Changes in behaviour, mood or personality.
• Confusion, or problems with memory and concentration.

Many of these symptoms are common and usually have other, far less serious causes, such as tiredness, stress, migraine or the side effects of other treatments. Having them does not mean the cancer has spread to your brain. But if you have new or worsening symptoms like these, it is important to tell your treatment team or GP so they can be checked.

Some symptoms need urgent attention. The NHS advises seeking emergency help, for example by calling 999 or going to A&E, if you have a seizure for the first time, a sudden severe headache unlike any you have had before, sudden weakness or numbness, or sudden problems with speech or vision. Tell the medical team that you have breast cancer.

How brain metastases are diagnosed

If your team thinks breast cancer may have spread to your brain, they will arrange scans to find out what is happening. The main test is a brain scan. According to Cancer Research UK and Breast Cancer Now, the scans used can include:

• An MRI scan, which uses magnets and radio waves to make detailed pictures of the brain. This is often the best scan for showing secondary cancer in the brain.
• A CT scan, which uses X-rays to build up cross-section pictures of the brain. This may be used first, especially in an emergency.
• Occasionally a lumbar puncture, where a thin needle is used to take a sample of the fluid around the spinal cord. This may be done if the cancer is thought to affect the lining of the brain and spinal cord (called leptomeningeal metastases).

You will not usually need all of these tests. Your team will explain which scans they recommend and why. Waiting for tests and results can be a very worrying time. Your breast care nurse is there to answer your questions and support you and your family while you wait.

Steroids and medicines to ease symptoms quickly

When breast cancer spreads to the brain, much of the trouble it causes comes from swelling (oedema) in the brain tissue around it. Easing this swelling can quickly improve symptoms such as headaches, sickness and weakness, while longer-term treatment is planned.

Steroids, such as dexamethasone, are often one of the first medicines given. Breast Cancer Now explains that steroids reduce swelling and pressure in the brain, which can relieve symptoms within a day or two. They are usually taken as tablets, starting at a higher dose and then reduced gradually as your team advises. It is important not to stop steroids suddenly, and to take them exactly as prescribed. Steroids can cause side effects such as a bigger appetite, difficulty sleeping, mood changes and raised blood sugar, so your team will use the lowest dose that keeps your symptoms under control.

If you have seizures, your doctor may prescribe anti-epileptic (anti-seizure) medicines to help keep them under control. Anti-sickness medicines and good pain relief can also help you feel more comfortable. Tell your team about any new symptoms, as the medicines can usually be adjusted to help.

Radiotherapy for brain metastases

Radiotherapy uses carefully targeted high-energy rays to destroy cancer cells. It is one of the main treatments for secondary breast cancer in the brain. There are two main types, and which one is suitable depends on how many areas of cancer there are, their size and where they are.

• Stereotactic radiosurgery or stereotactic radiotherapy. Despite the name, this is not surgery. Cancer Research UK explains it delivers a high dose of radiation very precisely to a small area, while sparing as much healthy brain tissue as possible. It may be used when there is a single area, or only a few small areas, of cancer in the brain. It is often given as one session or a small number of sessions, tends to cause fewer side effects than whole-brain radiotherapy, and can sometimes be repeated if cancer comes back.
• Whole-brain radiotherapy, which treats the whole brain. This may be used when there are several areas of cancer, or areas that are harder to target precisely. It is usually given as a short course of treatments over a few days. Side effects can include tiredness, hair loss in the treated area and a sore scalp.

Radiotherapy itself is painless, although the benefit can take a couple of weeks to be felt. Your team will explain what to expect, how many sessions you are likely to need and how to manage any side effects, such as tiredness, which can build up during and after treatment.

Surgery and drug treatments

Surgery is not suitable for everyone, but it may be an option for some people. Breast Cancer Now explains that an operation to remove the cancer may be considered if there is just one area, or only a few areas, of cancer in the brain that the surgeon can safely reach. Surgery may help to relieve symptoms, confirm the diagnosis and remove as much of the cancer as possible. It is often followed by radiotherapy to the area. A neurosurgeon and your oncologist will talk through whether an operation is right for you.

Drug treatments that work throughout the body are also important. The drugs chosen depend on the features of your cancer, such as whether it is hormone receptor positive or HER2 positive, and on your previous treatments. According to the NHS and Cancer Research UK, these can include:

• Hormone (endocrine) therapy, for cancers that are hormone receptor positive.
• Targeted therapies for HER2 positive breast cancer. Some of these are designed to reach the brain. For example, the targeted drug tucatinib, given with trastuzumab and the chemotherapy capecitabine, is recommended by NICE in England for some people with HER2 positive advanced breast cancer after two or more previous anti-HER2 treatments, and trials showed a benefit for people whose cancer had spread to the brain.
• Chemotherapy, which may be used to help control the cancer in the brain and elsewhere in the body.
• Newer treatments such as antibody-drug conjugates, which may be options for some people depending on the type of breast cancer.

These treatments can keep the cancer under control, and your team will review how well they are working with regular scans and check-ups. If one treatment stops working, there are often others to try. Your oncologist can explain which options are suitable for your particular cancer, and whether a clinical trial might be available to you.

Supportive care and living well

Alongside treatment to control the cancer, supportive care focuses on helping you feel as well as possible. This can include good pain relief, anti-sickness medicines, help with tiredness, and support for memory or concentration problems. Occupational therapists, physiotherapists and speech and language therapists can all help you stay as independent and safe as possible at home.

Palliative care teams are experts in controlling symptoms and supporting wellbeing for you and your family. Being referred to a palliative care team does not mean treatment is stopping; it simply adds extra support to help you live as well as possible. Your breast care nurse and many UK charities can also offer emotional support, practical advice and information.

It is natural to feel frightened or overwhelmed by a diagnosis of secondary breast cancer in the brain. Talking to your team about what to expect, and asking the questions that matter to you, can help you feel more in control. Some people find it helpful to talk to a counsellor, a support group or others going through something similar.

Practical issues matter too. If you have seizures or other symptoms, the law requires you to tell the DVLA and stop driving for a time, so ask your team for advice about driving. Your team and a benefits adviser can also help with work, money and planning for the future.

The scans, drugs and specialist care described here are not equally available everywhere, and some people face longer waits or other barriers to getting them. Charities like ours work to improve early detection and fair access to diagnosis and treatment for underserved communities, so that more people are diagnosed earlier and can get the support they need.