A metastatic brain tumor is a cancer that has spread to the brain from another part of the body. Cancer can spread, or metastasize, when cells break off from the original cancer and travel through the bloodstream.
Brain metastases are the most common type of brain tumor. An estimated 170,000 metastatic brain tumors are diagnosed in the United States each year.
One or multiple tumors, or lesions, can occur. Patients with existing cancer are at risk of developing a metastatic brain tumor, and as patients live longer with their primary cancer, they have a higher likelihood of developing metastatic tumors in the brain.
Tumors most likely to spread to the brain are those originating in the lung and breast. Melanoma, renal, gastrointestinal and pelvic cancer also commonly metastasize to the brain, although brain metastasis can occur from any tumor site in the body.
If a patient with cancer has symptoms that suggest that the cancer has spread to the brain, the patient’s physician will work with a team of specialists to confirm the diagnosis. A specialist will conduct a neurological examination, followed by CT scans and/or an MRI. These tests will help determine the size and location of the tumor. The diagnosis can be confirmed by a biopsy.
Brain tumor specialists today are capable of controlling many metastatic brain tumors with a combination of treatments, including chemotherapy, surgery, implant therapy (radiation seeds) and stereotactic radiosurgery.