Brain Metastases

What is brain metastases?

Brain metastases are cancer deposits in the brain that started somewhere else in the body. The word metastasis (plural: metastases) means the spread of cancer from its original site, called the primary tumor, to a distant organ. When cancer cells travel through the bloodstream and settle in the brain, they form one or more secondary tumors. These are not brain cancers in the strict sense; they are made of the same type of cell as the original cancer. A brain tumor from breast cancer, for example, is made of breast cancer cells growing inside the brain, and it is usually treated with that in mind.

Brain metastases are the most common type of tumor found in the adult brain, far more common than tumors that begin in the brain itself. They mainly affect adults who already have a known cancer diagnosis, although in some cases the brain tumor is the first sign that a cancer exists. Any cancer can spread to the brain, but some do so more often than others, including lung cancer, breast cancer, melanoma (a skin cancer), kidney cancer and colorectal cancer.

A person may develop a single brain metastasis or many. The number, size and location of the deposits, together with the type of primary cancer and the person’s general health, shape both symptoms and treatment decisions. Care usually involves several specialists working together, including oncologists (cancer doctors), radiation oncologists (doctors who treat cancer with radiation) and neurosurgeons (surgeons who operate on the brain and spine).

Brain metastases symptoms

Brain metastases symptoms depend largely on where the tumors sit, how big they are and how much swelling they cause in the surrounding brain tissue. Some people have no symptoms at all and the deposits are found on a routine scan. Others notice changes that build up over days or weeks. Common symptoms include:

• Headaches, often worse in the morning or when lying down, and sometimes accompanied by nausea or vomiting
• Seizures (sudden bursts of abnormal electrical activity in the brain that may cause shaking, staring spells or loss of awareness)
• Weakness or numbness in an arm, a leg or one side of the face or body
• Difficulty with balance, coordination or walking
• Problems with speech, such as slurred words or trouble finding the right word
• Changes in vision, including blurred or double vision or loss of part of the visual field
• Confusion, memory problems or difficulty concentrating
• Changes in mood, personality or behavior
• Unusual tiredness or drowsiness

Because the brain controls specific functions in specific areas, the pattern of symptoms often gives doctors a clue about location. A tumor near the part of the brain that controls movement may cause weakness; one in the back of the brain, called the cerebellum, may cause unsteadiness; one in the language areas may affect speech. Larger tumors and those with a lot of surrounding swelling tend to raise pressure inside the skull, which is the usual reason for headaches, nausea and drowsiness.

Symptoms can also differ by the underlying cancer. A brain tumor from breast cancer or from lung cancer may appear years after the original diagnosis, or sometimes at the same time. Melanoma metastases have a tendency to bleed, which can cause sudden symptoms. In some people the first sign is a seizure in someone who has never had one before, which always needs prompt medical attention.

Causes and risk factors

Brain metastases are caused by cancer cells breaking away from a primary tumor, entering the bloodstream and lodging in the brain, where they begin to grow. The brain has a protective barrier of tightly packed blood vessel cells, known as the blood-brain barrier, that limits which substances can pass from the blood into brain tissue. Cancer cells that reach the brain have found a way through or around this barrier. The same barrier is also one reason some cancer drugs work less well in the brain than elsewhere in the body.

The main risk factor is simply having a cancer that is known to spread to the brain. Factors that increase the likelihood include:

• Type of primary cancer, with lung cancer, breast cancer, melanoma, kidney cancer and colorectal cancer among the most common sources
• Advanced stage of cancer, especially when it has already spread to other organs such as the lungs, liver or bones
• Certain biological features of the tumor, such as specific gene changes or receptor patterns, which doctors identify through laboratory testing of the tumor
• Longer survival with advanced cancer, since better control of disease elsewhere in the body gives cancer more time to reach the brain
• A previous brain metastasis, which raises the chance of new deposits forming later

There is nothing a person does or fails to do that causes cancer to spread to the brain. Lifestyle habits that reduce the risk of cancer in general, such as not smoking, may lower the chance of developing the primary cancers most often involved, but once a cancer exists its spread is not within the patient’s control.

Diagnosis

Doctors confirm brain metastases mainly through imaging, combined with a careful history and a neurological examination. The examination checks strength, sensation, reflexes, coordination, vision, speech and thinking. The key tests include:

• MRI (magnetic resonance imaging) of the brain with contrast dye. This is the most sensitive standard test for detecting brain metastases, showing the number, size and location of deposits and any surrounding swelling. Contrast is a liquid given through a vein that makes tumors stand out more clearly.
• CT (computed tomography) scan. A quick X-ray-based scan often used in emergency settings, for example after a seizure or sudden weakness, or when MRI is not possible.
• Body imaging, such as CT of the chest and abdomen or a PET scan (a scan that highlights areas of high cell activity), to find the primary cancer if it is not already known and to see how widespread the disease is.
• Biopsy, in which a small sample of tumor tissue is removed and examined under a microscope. A biopsy may be needed when there is no known cancer, when the scan appearance is unclear, or when doctors need to confirm that a brain lesion is a metastasis rather than a primary brain tumor, an infection or radiation-related change.
• Laboratory tests on tumor tissue to identify specific molecular features that may guide the choice of drug treatment.

In many people with a known cancer, the typical appearance on MRI is enough to make the diagnosis without a biopsy. Doctors also assess the person’s overall level of functioning and the state of the cancer elsewhere in the body, because these factors weigh heavily in treatment planning and in discussions about brain metastases prognosis.

Brain metastases treatment options

Brain metastases treatment aims to control the tumors in the brain, relieve symptoms, protect brain function and maintain quality of life. The plan is individualized and usually decided by a team of specialists. The main options are described below, and several are often combined.

Medication to control symptoms. Corticosteroids (anti-inflammatory steroid drugs such as dexamethasone) are commonly used to reduce swelling around the tumors, which can quickly ease headaches, nausea and some neurological symptoms. Anti-seizure medicines are prescribed for people who have had a seizure. These drugs treat the effects of the tumors rather than the tumors themselves.

Radiation therapy. Radiation uses high-energy beams to damage cancer cells. Two main approaches are used. Stereotactic radiosurgery is a highly focused form of radiation that delivers a strong dose to each tumor while sparing most of the surrounding brain; despite its name, no cutting is involved, and it is often used for a limited number of small or medium-sized metastases. Whole-brain radiation therapy treats the entire brain over a series of sessions and may be considered when there are many deposits. Doctors weigh its benefits against possible effects on memory and thinking, and techniques that protect the memory center of the brain are sometimes used.

Surgery. A neurosurgeon may recommend removing a metastasis when it is large, causing significant pressure or symptoms, in a location that can be reached safely, or when tissue is needed to confirm the diagnosis. Surgery is often followed by focused radiation to the area to lower the chance of regrowth. At Acibadem, such operations are carried out within the neurosurgery department in coordination with the oncology team.

Systemic drug therapy. This means treatment that travels through the whole body, including chemotherapy, targeted therapy (drugs aimed at specific gene changes in the cancer) and immunotherapy (drugs that help the immune system attack cancer). Some newer targeted drugs and immunotherapies are able to reach the brain and shrink metastases in selected cancers, including certain types of breast cancer, lung cancer and melanoma. Whether this is an option depends on the primary cancer and its molecular features.

Observation. For very small deposits that cause no symptoms, especially when a drug treatment that reaches the brain is already working, doctors may sometimes recommend close monitoring with repeat MRI scans rather than immediate local treatment.

Rehabilitation and supportive care. Physical therapy, occupational therapy and speech therapy can help people regain strength, balance, daily skills and communication after treatment or when symptoms have caused lasting deficits. Palliative care, which focuses on relieving symptoms and stress at any stage of illness, is an important part of treatment and is not the same as end-of-life care.

Living with brain metastases and outlook

Brain metastases prognosis, meaning the likely course of the illness, varies widely from person to person. It depends on the type of primary cancer and its molecular features, how well the cancer elsewhere in the body is controlled, the number and size of brain deposits, the person’s age and general health, and how well they are functioning day to day. Historically the outlook after brain metastases was poor, and for many people it remains a serious diagnosis. However, advances in focused radiation, surgery and drugs that reach the brain mean that some people now live for extended periods with good control of their brain disease, particularly with certain breast, lung and melanoma cancers. Your doctor is the best person to discuss what the outlook may be in your specific situation, and it is reasonable to ask directly.

Living with brain metastases usually involves regular follow-up MRI scans to check for new or growing deposits, ongoing management of the primary cancer, and attention to symptoms. Fatigue, difficulties with memory or concentration, and changes in mood are common and can be helped with rehabilitation, counseling and practical adjustments at home and work. Many people are advised not to drive for a period after a seizure or brain surgery, in line with local regulations. Support from family, friends, patient organizations and mental health professionals can make a meaningful difference, and it is important to tell your care team about any new symptom rather than waiting for the next appointment.

Frequently asked questions

What are the first symptoms of brain metastases?

There is no single first symptom. Some people notice a new or changing headache, while others first experience a seizure, weakness on one side, unsteadiness, vision changes or confusion. Some have no symptoms and the metastases are found on a scan done for another reason. Any new neurological symptom in a person with cancer should be reported to a doctor promptly.

Can brain metastases be cured?

In most cases brain metastases are considered a sign of advanced cancer, and treatment is aimed at control rather than cure. That said, a single metastasis that is completely removed or treated with focused radiation can sometimes be controlled for a long time, and drugs that reach the brain have improved outcomes in certain cancers. How realistic long-term control is depends on the individual situation and should be discussed with the treating team.

How is a brain tumor from breast cancer treated?

A brain tumor from breast cancer is treated as breast cancer that has spread, not as a primary brain tumor. Options may include focused radiation, surgery for a large or symptomatic deposit, and drug treatments chosen according to the breast cancer’s receptor pattern, some of which can act on tumors inside the brain. The exact combination depends on the number of deposits, the person’s symptoms and how the cancer is behaving elsewhere in the body.

What is the prognosis with brain metastases?

Brain metastases prognosis varies greatly. Factors that generally point toward a better outlook include a small number of deposits, good day-to-day functioning, well-controlled cancer outside the brain, and a cancer type for which effective brain-penetrating drugs exist. Because these factors differ so much between people, general figures found online may not apply to you, and your own oncologist can give a more meaningful picture.

Is brain metastases treatment painful?

Stereotactic radiosurgery and whole-brain radiation are painless during delivery, although side effects such as tiredness, hair loss in treated areas or temporary swelling may occur. Surgery involves recovery time and some discomfort, which is managed with pain medicine. Steroids and drug therapies have their own side effects that your team will explain and monitor.

Do brain metastases always cause headaches?

No. Headaches are common but not universal. Many people with brain metastases never have a headache, and most headaches in general are not caused by tumors. Headaches that are new, steadily worsening, worse in the morning or accompanied by vomiting or neurological changes are the ones that need medical assessment.

How often will I need scans after treatment?

Follow-up MRI scans are usually done at regular intervals after treatment to check for new deposits or regrowth, with the timing set by your care team based on the type of cancer and the treatments used. Scans may become less frequent over time if the brain remains stable, but they are typically continued as long as the underlying cancer is active.

When to see a doctor

Anyone with a history of cancer who develops new neurological symptoms should contact their oncology or medical team without delay, even if the symptoms seem mild. Some situations need emergency care. Seek urgent medical attention if you or someone you are with experiences:

• A first-ever seizure, or a seizure that lasts more than a few minutes or repeats without recovery in between
• Sudden weakness, numbness or drooping on one side of the face or body
• Sudden difficulty speaking, understanding speech or finding words
• Sudden severe headache, especially with vomiting, stiff neck or drowsiness
• Sudden loss of vision or double vision
• New confusion, unusual behavior or difficulty staying awake
• Loss of consciousness or a fall with head injury
• Rapidly worsening balance or inability to walk

These signs can indicate bleeding, rising pressure inside the skull or another emergency that requires immediate assessment. For less sudden changes, such as gradually worsening headaches, increasing tiredness or new memory problems, an early conversation with your doctor allows adjustments to treatment before problems become severe.