What is a brain metastasis?
Metastatic brain tumors begin as cancer in another part of the body and spread to the brain through the blood stream. There can be one tumor or multiple tumors. The most common cancers that spread to the brain are lung (50%), breast (15-20%), skin melanoma (10%), kidney and colon (5%). A metastatic brain tumor may also be referred to as a “secondary tumor. When a skin cancer metastasizes to the brain, the “brain tumor” is actually a mass of skin cancer cells.
Some brain metastases appear years after the primary cancer. Others metastasize so quickly that they are discovered before the primary cancer. If the primary cancer cannot be found, it is called an “unknown” primary. A diagnostic work-up with imaging scans may be done to look for the primary cancer site. Treatment options vary depending on the location and number of brain lesions along with the location and severity of the primary cancer.
What are the symptoms?
Symptoms of a metastasis are related to the location of the brain in which they occur and may include headaches, physical numbness or weakness, disorientation, imbalance, and seizures. Cognitive problems may include short-term memory difficulty, problems talking (aphasia), or personality and behavior changes. A metastatic brain tumor is usually found when a cancer patient begins having neurological symptoms and a brain scan is ordered.
Who is affected?
Metastatic (secondary) brain tumors are fine times more common than primary brain tumors. About 10% to 30% of people with cancer develop a brain metastasis. There has been an increase in metastatic lesions as people are surviving cancers for longer periods of time.
How is a diagnosis made?
An MRI scan of the brain is the diagnostic tool of choice. An MRI showing multiple lesions is very suggestive of metastatic tumors. A diagnostic work-up may be performed to look for the primary cancer site. This work-up often including a chest x-ray, CT scan of the chest, abdomen, and pelvis, or a mammogram. A PET scan be performed.
If a suspicious site for primary cancer is identified, oftentimes that site is biopsied first to help direct treatment. If there is a prior history of cancer, a biopsy may not be necessary. If the primary cancer cannot be identified, then a brain biopsy or surgery to remove the tumor may be performed to determine the diagnosis.
What treatments are available?
- Medications – used to help relieve symptoms
- Radiation – using controlled high-energy rays to damage the DNA inside the cells, preventing them from dividing and growing.
- Surgery – recommended for patients who have 1 or 2 metastatic brain lesions and are in good health, with primary cancer that is treatable.
- Chemotherapy – drugs that work to interrupt cell division. Chemo is delivered in cycles to allow the body to rest in between.
If you have any questions or would like to schedule an appointment with one of our Spine Center specialists, please call 515.875.9560.
American Brain Tumor Association – www.ABTA.org
National Brain Tumor Society – braintumor.org