What is a Metastatic Brain Tumor?

Types of metastatic tumors:

Metastatic brain tumors are called secondary brain tumors as they are caused by cancer cells spreading (metastasizing) from another area of the body through the bloodstream to the brain. Metastatic brain tumors are five times more common than primary brain tumors. The most common types of cancer that cause metastatic brain tumors are lung cancer, breast cancer, melanoma (skin cancer), colon cancer, kidney (renal) cancer, and thyroid cancer. Metastatic brain tumors are always malignant (cancerous).

This type of tumor begins to grow in another part of the body (the primary cancer), then spreads (metastasize) to the brain. This occurs when cancer cells break away from the primary tumor and travel to the brain, usually through the bloodstream. The tumor cells then commonly go to the part of the brain called the cerebral hemispheres, or to the cerebellum. Cancer can also spread to the spine (metastatic spine tumors). Metastatic brain tumors can grow rapidly, crowding or destroying nearby brain tissue. Sometimes, a patient may have multiple metastatic tumors in several different areas of the brain.

Some metastatic brain tumors appear many years after the primary cancer. Others metastasize so quickly that they are identified before the primary cancer. In other cases, the body is able to destroy the primary cancer but not the metastatic brain tumor. When this occurs, the primary cancer is often unknown.

The main treatments for metastatic brain (or spine) tumors are:

• Surgery (tailored, individualized and/or radiosurgery)
• Radiation therapy (radiosurgery and/or radiotherapy)
• Chemotherapy

A patient may receive one or both treatments. Learn more about treatment for metastatic brain and spine tumors.

Causes of metastatic brain tumors:

Metastatic brain tumors are caused by cancer cells elsewhere in the body that spread (metastasize) through the bloodstream to the brain. About one-third of patients with another type of cancer will develop one or more metastatic brain tumors. The risk for metastatic brain tumors begins to increase in people ages 45 to 65, and is highest in those over 65.

For more information, contact the Johns Hopkins Metastatic Brain Tumor Center at 410-955-6406.