Cancer that starts in one part of the body and spreads to the brain is called brain metastases. It’s sometimes called secondary brain cancer or a metastatic brain tumour. Cancer that starts in the brain is called primary brain cancer. Brain metastases are much more common than primary brain cancer.
Metastatic cancer is also called:
- metastatic tumour, tumours or disease
- metastasis (one cancerous tumour)
- metastases (more than one cancerous tumour)
- advanced cancer
Any type of cancer can spread to the brain. The most common types of cancer that spread to the brain are:
- lung – accounts for about half of all brain metastases
Cancer can spread to any part of the brain. The most common place for brain metastases is the cerebrum, which is the largest and top part of the brain. Less often, cancer spreads to the cerebellum and brain stem. Sometimes there is only a single brain metastasis, but most people develop many brain metastases.
The symptoms of brain metastases vary depending on which part of the brain is affected. Other health conditions can cause the same symptoms as brain metastases. See your doctor if you have these symptoms.
The most common symptom of brain metastases is a headache. Headaches may be caused by a tumour pressing on the brain, swelling caused by a fluid buildup around the brain (called edema), bleeding or hydrocephalus.
Other signs and symptoms of brain metastases include:
- nausea and vomiting
- weakness or numbness in parts of the body, such as the face, arms or legs
- confusion and problems with memory
- changes in behaviour and personality
- problems with balance and coordination
- loss of bladder or bowel control (called incontinence)
- problems with speech
- problems with swallowing
Diagnosis is the process of finding out the cause of a health problem. The following tests may be used to diagnose brain metastases. Many of the same tests can help your healthcare team plan treatment and watch for changes to the cancer.
Health history and physical exam
Your health history is a record of your symptoms, risks and all the medical events and problems you have had in the past. Your doctor will ask questions about a personal history of symptoms that suggest brain metastases.
A physical exam allows your doctor to look for any signs of brain metastases. Your doctor may test your reflexes and check the feeling and strength you have in your arms and legs. The doctor may also look into your eyes using a special tool with a light (called an ophthalmoscope) to see if the nerve at the back of the eye is swollen.
Find out more about a physical exam.
Magnetic resonance imaging (MRI) is used to check for tumours in the brain. It is usually the first test done to check the reason for symptoms like headaches and seizures. It can identify the number, location and size of metastases. An MRI can find very small tumours and tumours that are deeper in the brain.
Find out more about MRIs.
If an MRI can’t be done, a computed tomography (CT) scan is used to check for tumours in the brain. An MRI can’t be used when there are certain metal devices inside the body, like a pacemaker.
Find out more about CT scans.
A biopsy is a test that removes cells or tissues so they can be examined under a microscope. If you have a history of cancer, doctors can often diagnose brain metastases based on the results of imaging tests so a biopsy isn’t usually needed. A biopsy may be done after imaging tests if you have never had cancer or if the doctor thinks that there might not really be brain metastases.
If you need to have a brain biopsy, you are usually referred to a neurosurgeon. The neurosurgeon decides which type of biopsy will be best for your situation. An excisional biopsy or stereotactic biopsy may be used.
Find out more about biopsies.
Blood tests are usually done to check your general health and find out how some organs are working. These tests may also find out if cancer has spread to organs other than the brain.
A complete blood count (CBC) is done to check your general health and how well the bone marrow is working.
Liver function tests are done to look for any problems with the liver.
An electrolyte panel measures sodium, potassium, chloride, magnesium, phosphate and bicarbonate. It helps find problems with the kidneys.
If brain metastases are found before the primary cancer is diagnosed, the doctor may order tests to find out where the cancer started. Other tests may also be used to check for metastatic cancer in other parts of the body. These tests include:
- a chest x-ray to check for lung cancer
- a PET scan to look for cancer in other parts of the body
- tumour markers to try to identify where the cancer started
Treatments and supportive therapies
If you have brain metastases, your healthcare team will create a treatment plan just for you. It will be based on your needs and usually includes a combination of different treatments. Treatments can control and slow the growth of brain metastases, but the metastases usually don’t go away completely. They can also manage or prevent problems caused by brain metastases. These treatments are called supportive therapies.
When deciding which treatments and supportive therapies to offer for brain metastases, your healthcare team will consider:
- where the cancer started
- your symptoms
- how well you can do daily activities (called performance status)
- how many metastases are in the brain and how big they are
- where the metastases are within the brain and spinal cord
- if you have metastases in other parts of the body
- the prognosis (expected outcome)
- what you prefer or want
You may be offered the following treatments and supportive therapies for brain metastases.
Corticosteroids are medicines used to reduce swelling and pressure in and around the brain. They are often the first supportive therapy given to manage symptoms of brain metastases such as headaches and neurologic problems. Corticosteroids can be used alone or along with other treatments like radiation therapy and surgery. They are given intravenously (through a needle into a vein) or orally (as a pill by mouth).
The most common corticosteroid used for brain metastases is dexamethasone (Decadron). It is usually given at least twice a day until symptoms are relieved. Then the dose is slowly lowered to prevent long-term side effects.
Side effects of corticosteroids will depend mainly on the dose and the length of treatment. Common side effects are sleep problems, increased appetite, fluid buildup in the legs, arms or face, weight gain, high blood sugar levels, infection, mood changes and skin problems like a rash or acne.
External radiation therapy is a common treatment for brain metastases. It can be given to the whole brain or to very specific areas of the brain. Radiation therapy can be used alone or in combination with other treatments such as surgery. Dexamethasone is usually given before and after radiation therapy, to help reduce swelling in the brain caused by radiation.
Whole-brain radiation therapy (WBRT) is external radiation directed through the scalp and skull to the entire brain. It is the standard treatment when there are many metastases in the brain. WBRT may be given before or after surgery is done to remove a single metastasis. How long WBRT is used depends on things like the number of metastases and how severe the symptoms are. It is usually given once a day for 5 or 10 days.
Stereotactic radiosurgery (SRS) is a type of external radiation therapy that creates many small, thin beams of radiation from different angles that meet at the tumour to give the highest dose to the tumour. It avoids the healthy brain tissue around the tumour. SRS may be used when there are 1 to 3 small brain metastases. It may also be used after surgery to treat the edges of the tissues where the brain metastases were removed.
Side effects of radiation therapy will depend mainly on the type of radiation therapy, the area of the brain being treated and the length of treatment. Common side effects of radiation therapy to the brain are hair loss, fatigue and memory problems.
Find out more about radiation therapy.
Surgery is a standard treatment when there is one brain metastasis that can be safely removed and the primary cancer is not growing or spreading. Sometimes surgery will be done to remove more than one tumour if there are only a few tumours or they are close together. Surgery may also be done to remove a larger tumour that is causing symptoms, while leaving the smaller ones to be treated with radiation therapy.
Whole-brain radiation therapy is often done after surgery. Stereotactic radiosurgery may also be used after surgery to treat the edges of the tissue where the brain metastasis was removed.
The type of surgery done for brain metastasis is called a craniotomy. The neurosurgeon temporarily removes part of the skull to reach the brain and remove the metastasis.
Side effects of surgery will depend mainly on the location of the brain metastases. They include bleeding, swelling of the brain and seizures.
Find out more about surgery.
Anticonvulsants are medicines used to control seizures. They are also called antiseizure or anti-epileptic drugs. People with brain metastases who have seizures at diagnosis or develop seizures during treatment are usually started on anticonvulsants. They are most often given over a long period of time. Anticonvulsants are not given to people with brain metastases who have never had a seizure.
The type of anticonvulsant used depends on the type of seizures, how often they happen, how long they last and other medicines being used. Some anticonvulsants interact with other medicines, which changes the levels of the drugs in the body.
Anticonvulsants are usually given as a pill by mouth. Some may be given through a needle into a vein. Anticonvulsants used for brain metastases include:
- phenytoin (Dilantin)
- carbamazepine (Tegretol)
- valproic acid (Depakene, Epival)
- oxcarbazepine (Trileptal)
- levetiracetam (Keppra)
- phenobarbital sodium (Phenobarb)
Side effects of anticonvulsants will depend mainly on the type and dose of the drug. Some side effects are nausea and vomiting, skin problems (such as a rash), sleepiness, dizziness, problems with memory, problems with speech and liver damage.
Chemotherapy may be used to treat brain metastases, but it’s not a common treatment. It’s usually offered after all other treatments have been tried and is usually given along with other treatments, such as radiation therapy. Doctors only use chemotherapy to treat brain metastases when they know that the primary cancer is likely to respond to chemotherapy.
Chemotherapy drugs circulate (flow) throughout the body and destroy cancer cells. The drugs, dose and schedule will vary for each person. The type of chemotherapy drug or combination of drugs used depends on where the cancer started and if the drugs can cross the blood-brain barrier. This barrier prevents toxic substances, like chemotherapy drugs, from entering the brain and spinal cord. Many chemotherapy drugs can’t cross the blood-brain barrier in large enough doses to treat brain metastases.
Side effects of chemotherapy will depend mainly on the type of drug, the dose and how it’s given. Common side effects include low blood cell counts (called bone marrow suppression), nausea and vomiting, mouth problems and bowel problems.
Find out more about chemotherapy.
Targeted therapy uses drugs that find and attach to specific substances (such as proteins) on the surface of cancer cells or inside cancer cells. These substances help send signals that tell cells to grow or divide. The targeted therapy drugs block the substances to stop or slow the growth and spread of cancer cells.
The type of targeted therapy drug used will depend on where the cancer started.
Side effects of targeted therapy depend mainly on the type and dose of the drug. Common side effects include flu-like symptoms and fatigue. Most side effects go away on their own or can be treated. Tell your healthcare team if you have these side effects or others you think might be from targeted therapy.
Find out more about targeted therapy.
Immunotherapy boosts the immune system or helps the immune system to find cancer and attack it. Immunotherapy may be given as a treatment on its own, but it is most often used with other types of therapy such as chemotherapy and radiation therapy.
The type of immunotherapy drug used will depend on where the cancer started.
Side effects of immunotherapy depend mainly on the type and dose of the drug. Common side effects include flu-like symptoms and fatigue. Most side effects go away on their own or can be treated. Tell your healthcare team if you have these side effects or others you think might be from immunotherapy.
Find out more about immunotherapy.
Clinical trials look at new ways to prevent, find or treat cancer. Talk to your healthcare team about clinical trials open for people with metastatic cancer. Find out more about clinical trials.
If you can’t have or don’t want cancer treatment
You may want to consider a type of care to make you feel better without treating the cancer itself. This may be because the cancer treatments don’t work anymore, they’re not likely to improve your condition or they may cause side effects that are hard to cope with. There may also be other reasons why you can’t have or don’t want cancer treatment.
Talk to your healthcare team. They can help you choose care and treatment for advanced cancer.
Living with brain metastases
A diagnosis of brain metastases can often cause a great amount of fear and anxiety. A person with brain metastases may have concerns about the following.
Brain metastases often cause problems with the body’s functions and movements. The type of neurological problems that happen depend on the part of the brain affected. These problems include:
- difficulty walking
- muscle weakness
- poor balance and coordination
- loss of memory and concentration
- changes in mood and behaviour
- problems with speech, swallowing or vision
Neurological problems can lead to stress and worry about losing your sense of self and your independence. Some treatments and supportive therapies can help manage and control neurological problems. Your healthcare team, including an occupational therapist and social worker, can also offer support and help you cope with any neurological problems.
A diagnosis of advanced cancer can lead to questions about survival. There is no way of knowing exactly how long someone will live with brain metastases. It depends on many factors, including the type of cancer, the number of metastases in the brain and the treatments used. Survival with brain metastases is often measured in months, but some people can survive for several years. Some people may live much longer than expected, while others may die sooner than expected.
The best person to talk to about your survival is your doctor. Your doctor may be able to estimate survival based on what they know about you and the type of cancer, but everyone responds differently to cancer and cancer treatments.
The largest part of the brain, which contains different areas that control muscle function, thought, speech, emotions and learning.
The cerebrum is divided into 2 parts (called hemispheres) that are connected by a bridge of nerve fibres called the corpus callosum.
The part of the brain at the back of the skull (between the cerebrum and brain stem) that controls movement, balance, reflexes and other complex motor functions.
The stalk-like part of the brain that connects to the spinal cord. It controls basic body functions, such as breathing, hunger, heart rate, blood pressure and consciousness.
The 3 areas of the brain stem are the midbrain, pons and medulla oblongata.
Abnormal buildup of cerebrospinal fluid (CSF) in the ventricles (fluid-filled cavities) of the brain.
A sudden involuntary muscle movement or convulsion caused by uncontrolled electrical activity in the brain. Symptoms include muscle twitches, staring, tongue biting, urination, loss of consciousness and total body shaking.
A type of biopsy in which all of the tumour or abnormal tissue is removed, along with a margin of tissue around it, for examination under a microscope.
A procedure that uses a 3-dimensional scanning machine (ultrasound, CT scan or MRI) to find the precise location of a tumour and remove a sample for examination under a microscope.
Stereotactic biopsy is most often used on brain and breast tumours.
The soft, spongy tissue inside most bones.
There are 2 main types of bone marrow. Red bone marrow is where blast cells (immature blood cells) develop into red blood cells, white blood cells and platelets. Yellow bone marrow stores fatty tissue.
A protective network of blood vessels and cells that filters blood flowing to the brain.
The blood-brain barrier makes it hard for some substances (such as anti-cancer drugs) to enter the brain.