Brain metastases happen when cancer cells from another part of the body spread to the brain, usually through the bloodstream. Certain factors may increase the chance of developing brain metastases, though these factors do not directly cause cancer. As many as 40 percent of people with advanced cancer develop metastases at some point, but treatment has evolved to improve outcomes and keep patients as comfortable as possible.
Cancers with increased risk of brain metastases are:
- Lung cancer: lung cancer is the most common source of brain metastases, especially small cell lung cancer but also non-small cell lung cancer.
- Breast cancer: breast cancer can also spread to the brain, particularly in people with HER2-positive or triple-negative breast cancer.
- Melanoma: About half of people with advanced melanoma (a type of skin cancer) develop brain metastases.
Other cancers that can spread to the brain include kidney cancer, gastrointestinal cancer such as esophageal cancer or colon cancer, gynecologic cancer, head and neck cancer, though this happens less often.
If you have cancer, it’s important to talk with your doctor about your risk and whether brain imaging or other follow-up care is needed.
Symptoms
Brain metastases can cause a wide range of symptoms. These depend on the size, number, and location of the tumors in the brain. As tumors grow, they press on nearby brain tissue, which can affect how the brain works. Some symptoms may appear slowly, while others come on suddenly.
Common symptoms of brain metastases include:
- Headaches: Caused by increased pressure inside the skull. Headaches are often worse in the morning and may improve later in the day.
- Seizures: Tumors can change the brain’s electrical signals. Seizures may cause muscle jerking or stiffness, trouble speaking, numbness or tingling, and changes in smell or taste.
- Speech problems: Tumors may cause difficulty speaking clearly, understanding others, or finding the right words.
- Vision changes: A tumor might cause vision loss, often on one side.
- Weakness or numbness: This can affect one side of the body, especially an arm or leg.
- Balance or walking problems: Tumors can affect coordination and make it harder to move safely.
- Memory loss or confusion: Brain metastases can affect thinking, short-term memory, and decision-making. There may also be noticeable changes in mood, personality, or behavior.
- Nausea and vomiting: Pressure in the brain can cause nausea or vomiting.
If you have new or changing symptoms, talk to your doctor. These signs can be caused by other conditions too—not just brain metastases. Your care team can help figure out the cause and recommend next steps.
Learn more about .
Prevention
Although brain metastases cannot be prevented, your care team will carefully monitor your primary cancer for any changes. Ask your doctor if they suspect your primary cancer may spread to your brain.
