Metastatic Brain Cancer

Nov. 14, 2025

This page was reviewed under our medical and editorial policy by Keng Lam, M.D., assistant clinical professor, Department of Medical Oncology & Therapeutics Research, City of Hope^® Cancer Center Duarte.

Metastatic brain tumors — also called brain metastases or secondary brain tumors — happen when cancer spreads to the brain from another part of the body. These are the most common type of brain tumor in adults.

Approximately 200,000 new cases of brain metastases are diagnosed in the United States each year, occurring equally in men and women. The risk of developing brain metastases increases with a diagnosis of certain cancers, such as breast cancer, lung cancer and melanoma.

Primary brain tumors, which originate in the brain itself, are much less common and mostly benign (noncancerous).

What Are Brain Metastases?

Brain metastases are a form of metastatic cancer. They occur when cancer cells break away from a tumor in another part of the body and travel to the brain — usually through the bloodstream. The original tumor is known as the primary tumor/cancer.

Researchers are still working to understand why some cancers — including lung cancer, breast cancer and melanoma — are more likely to spread to the brain than others.

Which Cancers Spread to the Brain?

While brain metastases can arise from nearly any type of cancer, some cancers are more likely to spread to the brain, including:

• Lung cancer: About half of people with lung cancer develop brain metastases, especially those with small cell lung cancer. In men, lung cancer is the most common source of brain metastases.
• Breast cancer: Around 10% to 15% of people with metastatic breast cancer develop brain metastases. These are more likely to occur in patients with HER2-positive or triple-negative breast cancer. In women, breast cancer is the most common cause of brain metastases.
• Melanoma: Up to 50% of people with melanoma, the deadliest skin cancer, develop brain metastases.

Other cancers, such as kidney, colon and thyroid cancer, may also spread to the brain, but this happens less often.

Symptoms of Brain Metastases

Symptoms of brain metastases vary depending on where the tumor is located and how it affects brain function. Most symptoms appear gradually and worsen over time.

The most common symptoms include:

• Headaches
• Seizures
• Numbness or tingling
• Coordination problems
• Cognitive problems, including mood changes and short-term memory loss
• Speech problems
• Vision problems, particularly on one side or the other
• Nausea or vomiting
• Muscle weakness

As the condition progresses, the patient may experience new or worsening symptoms, such as:

• Trouble hearing, swallowing or seeing clearly (like double vision)
• Drowsiness, which is the most common symptom in late-stage brain metastases

Treatment for Brain Metastases

Treatment for brain metastases depends on several factors, including the tumor’s size and type, where the cancer started, how far it has spread and the patient’s overall health.

The goals of treatment may include:

• Getting a clear diagnosis by examining tissue from the tumor
• Relieving symptoms
• Improving the ability to function
• Managing the cancer and any related brain tumors

Typically, treatment options for brain metastases fall into these categories:

• Medications to help manage symptoms like swelling, headaches or seizures
• Radiation therapy and surgery to shrink or remove tumors
• Cancer-fighting medications such as chemotherapy, targeted therapy or immunotherapy, depending on the primary cancer type

Symptom Management

The patient’s care team will likely begin by managing any immediate symptoms. For instance, they may prescribe:

• Corticosteroids to reduce brain swelling (edema) can cause headaches.
• Anticonvulsants to help control seizures.

Surgery and Radiation Therapy

Treatment options for brain metastases aim to slow tumor growth, relieve symptoms and improve the patient’s quality of life. These include:

• Stereotactic radiosurgery (SRS): SRS is the most common treatment for brain metastases in the United States. This precise, high-dose radiation targets the tumor while sparing healthy brain tissue. Most patients need just one session.
• Whole brain radiation therapy (WBRT): WBRT is often used when there are multiple tumors or if the cancer has spread to the brain’s membranes (leptomeningeal disease). Treatment usually involves 10 to 15 sessions over two to three weeks.
• Surgery: In some cases, traditional surgery may be recommended to remove one or more tumors, if they’re large and causing significant symptoms.

Drug Treatments

Depending on the type of primary cancer, the patient may also receive:

• Chemotherapy: While many chemo drugs can’t cross the blood-brain barrier, others may be able to. These may be administered intravenously or by mouth.
• Targeted therapy: These drugs block specific molecules cancer cells use to grow. Some types of lung and breast cancer brain metastases may respond well to this approach.
• Immunotherapy: These drugs help the patient’s immune system recognize and destroy cancer cells. Immunotherapy may be effective for some lung cancers and melanoma that spread to the brain.