What Is Metastatic Brain Cancer?

Metastatic brain cancer happens when cancer from one part of your body spreads to your brain. Metastatic brain cancer is cancer that has spread to the brain from a different part of the body. A person with metastatic brain cancer may experience a combination of physical, emotional, and cognitive symptoms, which will typically cause them to need supportive care and rehabilitation alongside medications. 

It is important to tell your doctor if you notice any unusual symptoms — such as lumps, blemishes, freckles, wart-like growths, or moles — on any part of your body. This is because early cancer diagnosis can improve the condition’s outcome by ensuring that care is provided at the earliest possible stage.

This article explains metastatic brain cancer and discusses its signs, symptoms, causes, diagnosis, and treatment options. 

Metastatic brain cancer occurs when cancer cells spread to the brain from another part of the body. This is also called a metastatic brain tumor or secondary brain tumor.

Metastatic brain cancer is different from primary brain cancer. The former is cancer that spreads from another part of the body to the brain, while the latter is one that originally developed in the brain.

Not all tumors are malignant. However, a tumor is described as malignant, or cancerous, if it has the potential to spread from one part of the body to the other. There are many different types of cancers that can spread to the brain. However, primary breast cancer, lung cancer, and skin cancer are more likely than other types to spread to the brain. 

According to the American Cancer Society (ACS), doctors will diagnose about 25,050 malignant brain or spinal cord tumors in 2022. However, the ACS also notes that a person’s chance of developing one of these conditions in their lifetime is less than 1%. 

Sometimes, metastatic brain cancer appears many years after the primary cancer. In some cases, however, metastatic brain cancer develops so quickly that it is identified before the primary cancer.

The speed at which the metastatic cancer spreads can depend on a range of different factors, such as the location of the primary cancerous cells. For instance, cancer cells with more access to the lymphatic system or blood may spread faster than cells that do not. 

The speed of growth and spread may also depend on the type of cancer that metastasized. One 2020 study found that the interval between primary cancer diagnosis and brain metastasis was 1.2 years for lung cancer, while it was 4.6 years for breast cancer. 

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Because it affects the brain, which is the major part of the central nervous system, metastatic brain cancer can cause physical, psychological, and cognitive symptoms. 

Physical symptoms include:

• nausea or vomiting
• headaches
• seizures
• vision problems
• muscle weakness
• bladder problems
• a loss of balance

Psychological symptoms include:

• anxiety
• anger
• numbness
• mood changes
• depression

Cognitive symptoms include:

• memory loss
• confusion
• an impaired sense of judgment
• speech disturbances
• issues processing information

Several different factors — such as having a certain type of primary cancer or being a certain age — can influence your chance of developing metastatic brain cancer.

For instance, according to a study that evaluated the natural growth rate of metastatic cancer to the brain, 10–40% of people with cancer develop brain cancer metastasis. Another article indicates that lung, breast, and skin primary cancers are more likely to spread to the brain. 

Also, according to a 2018 study that analyzed people with metastatic human epidermal growth factor receptor 2-positive breast cancer (HER2+ BC) between January 2000 and December 2014, people with the metastatic growth factor receptor often developed brain metastasis.

The study also found that risk factors for the development of brain metastasis in people with HER2+ BC included:

• a tumor size of greater than 2 centimeters
• the development of lung metastasis
• the invasion of lymph nodes by cancer cells
• an age less than or equal to 40 years 

Your doctor may suspect that you have brain metastasis after asking you some questions about your health. They may ask you questions regarding the symptoms you experience and how long the symptoms have lasted. Your doctor may also want to know if you have received treatment for cancer in the past and, if so, the cancer type.

Asking questions helps clinicians have a better idea of what the problem could be. However, they cannot conclusively say that you have metastatic brain cancer unless they run some tests.

Tests your doctor may recommend include:

• Imaging tests: Imaging tests such as MRI scans are often useful when diagnosing brain cancer. MRI creates images of soft tissue that may not be visible using other imaging techniques. Sometimes, clinicians use MRI with contrast dye to determine if a tumor is malignant.
• Neurological exams: It is not uncommon for doctors to carry out neurological exams such as tests for coordination, vision, balance, reflexes, and strength when diagnosing brain cancers.
• Biopsy: Biopsy involves removing a tiny tissue sample and examining it more closely to determine if it is cancerous or noncancerous. A biopsy will also help determine if the cancerous cells are from metastatic cancer or a primary tumor.

Brain metastasis treatment often focuses on slowing tumor growth, extending life, and easing symptoms. Treatment options for brain metastasis often include the following.

Healthcare professionals often prescribe medications to help ease the signs and symptoms of brain metastases. Your oncologist may give you antiseizure drugs if you experience seizures or steroid drugs to ease swelling.

This also involves the use of medications. In this case, however, you will be given special drugs to target and kill the cancer cells. Doctors can provide chemotherapy drugs orally or through a vein.

Different types of chemotherapy drugs are available. Your oncologist will prescribe the best one for you.

Along with chemotherapy, radiation therapy is one of the most effective treatments for most cancer types. Radiation therapy and chemotherapy have the same goal: to kill cancerous cells. However, radiation therapy involves using high doses of radiation beams to kill a malignant tumor. Radiation beams work by changing the DNA makeup of a tumor. This causes the tumor to shrink and die.

This treatment option uses the immune system to fight cancer cells. Sometimes, cancerous cells produce proteins that help them hide away from the body’s immune cells. Immunotherapy interferes with that process, enabling the immune system cells to find the cancer cells and fight them. 

Brain surgery is sometimes necessary to remove the brain tumor. This process is known as craniotomy, and it involves opening the skull to remove part or all of the tumor.

Learn more about treatment options for brain tumors here.

Cancer treatment has continued evolving over the years. This has been promising for outlook.

One 2020 study showed that the use of local therapies in people with HER2+ BC was vital in the initial management of metastatic brain cancer. The study also indicated improvements in survival with different brain metastasis diagnoses. However, it found that for breast cancer metastasis in the brain, survival varies between 3 and 36 months. 

It is possible for cancer that developed in another part of the body to spread to the brain.

The chance of this occurring varies with age. In some cases, brain metastasis spreads and grows so quickly that it may be diagnosed before the primary cancer.

If you notice any symptoms of brain cancer or any other kind of cancer, contact your doctor straight away.