What Are Metastatic Brain Tumors?

Metastatic brain tumors form from cancer cells that began elsewhere in the body, and are often called secondary brain tumors. The cancer cells break off from the primary tumor and enter the bloodstream or lymph system to travel throughout the body. Metastatic brain tumors can develop from cancer in any area of the body, such as the lung, breast, colon, kidney, or skin (melanoma).

Approximately 10 percent of all cancer cases will spread, or metastasize, to the brain. In Colorado, it’s estimated that approximately 20,000 new cases of metastatic brain tumors will be diagnosed this year.

Who Gets Metastatic Brain Tumors?

The incidence of metastatic brain tumors is highest in those over age 65, but begins to increase at age 45. The rate of metastasis depends on the type of primary cancer. For example, malignant melanoma (skin cancer) metastasizes in nearly 50 percent of people — and more commonly in men than women — while digestive system cancers spread to the brain in fewer than 10 percent of patients.

Metastatic brain tumors are rarely diagnosed before the primary cancer cause is identified. Brain cancer is typically found during a brain scan (CT or MRI) that is ordered when a cancer patient exhibits neurological symptoms such as:

• Dizziness
• Headaches
• Seizures
• Memory issues
• Problems with balance or speech
• Personality changes
• Blurred/double vision

Metastatic Brain Tumor Treatment Options

To determine the best treatment approach, doctors assess the growth and development of metastatic brain tumors based on:

• Your history of cancer and how your primary cancer is being managed
• Your overall health
• Number, size, and location of the metastatic brain tumor(s)
• Type of tissue or cells affected
• The likelihood that part or all of the tumor(s) can safely be removed by traditional surgery
• The spread of the cancer within the brain or spinal cord

The three main types of treatment are surgery, chemotherapy, and radiation. Steroids and antiseizure medications may also be used to help control symptoms.

• Gamma Knife surgery has proven to be a highly effective method to treat metastatic brain tumors with reliable and predictable local tumor control and improved survival rates. Published medical studies involving more than 4,800 patients with brain metastases have found that Gamma Knife treatment offers consistent and reproducible results with an average local tumor control between 84 and 97 percent. Today, radiosurgery is the primary management tool for intracranial metastatic disease.
• Surgery is often considered as a first option to remove the tumor(s) if it can be reached without excessive damage to the surrounding tissues, nerves, and structures. Image-guided surgery helps increase precision, but hemorrhaging and surgical site infection are associated risks.
• Chemotherapy is not often used alone to treat metastatic brain tumors because of drug resistance and the blood-brain barrier. However, it may be combined with other treatment options.
• Whole brain radiation is sometimes recommended for patients with large lesions deep in the brain and for those with multiple metastatic tumors. It is also often used in combination with open surgery or Gamma Knife and other types of stereotactic surgery. However, because of its negative effects on cognitive function, a recent large study led by a researcher at The University of Texas MD Anderson Cancer Center found that the risks were greater than the benefits when used as an adjuvant therapy.

Treatment

The best treatment option for your metastatic brain tumor(s) depends on many factors. Your doctor will help you make this decision based on:

• Your cancer history and how your primary cancer is being managed
• Your overall health
• Number, size, and location of the metastatic brain tumor(s)
• Type of tissue or cells affected
• The likelihood that part or all of the tumor(s) can safely be removed by traditional surgery
• The spread of the cancer within the brain or spinal cord

You also will want to discuss the goals of your treatment:

• Controlling your symptoms
• Shrinking the tumor(s) or stopping further growth
• Removing the tumor(s)

Learn more about the risks and benefits of treatment options for metastatic brain tumors.

Learn about treating metastatic brain tumors with Gamma Knife at Rocky Mountain Gamma Knife Center.