Some types of cancers rarely spread to the brain, such as colon cancer or prostate cancer.
Growing brain tumors may place pressure on nearby parts of the brain. Brain swelling due to these tumors also causes increased pressure within the skull.
Brain tumors that spread are classified based on the location of the tumor in the brain, the type of tissue involved, the original location of the tumor, and other factors. Rarely, a tumor can spread to the brain from an unknown location. This is called cancer of unknown primary (CUP) origin.
Metastatic brain tumors occur in about one-fourth of all cancers that spread through the body. They are much more common than primary brain tumors (tumors that start in the brain) and occur in 10 - 30% of adult cancers.
Note: Specific symptoms vary. The symptoms commonly seen with most types of metastatic brain tumor are those caused by increased pressure in the brain.
Signs and tests
An examination shows brain and nervous system (neurologic) changes based on where the tumor is located in the brain. Signs of increased pressure in the skull are also common. Some tumors may not show signs until they are very large. Then, they cause a very quick decline in nervous system function.
The original (primary) tumor may be found by examining tumor tissues from the brain.
Treatment depends on the size and type of the tumor, from where in the body it spread, and the patient's general health. The goals of treatment may be to relieve symptoms, improve functioning, or provide comfort.
Radiation to the whole brain is often used to treat tumors that have spread to the brain, especially if there is more than one tumor.
Surgery may be used for metastatic brain tumors when there is a single tumor and the cancer hasn't spread to other parts of the body. Some tumors may be completely removed. Tumors that are deep or that extend into brain tissue may be debulked (reduced in size).
Surgery may reduce pressure and relieve symptoms in cases when the tumor cannot be removed.
Chemotherapy for metastatic brain tumors is not as helpful as surgery or radiation.
Stereotactic radiosurgery is used at some hospitals. This form of radiation therapy focuses high-powered x-rays on a small area of the brain.
Anticonvulsants such as phenytoin or levetiracetam to reduce or prevent seizures
Corticosteroids such as dexamethasone to reduce brain swelling
Osmotic diuretics such as urea or mannitol to reduce brain swelling
When the cancer has spread, treatment may focus on relieving pain and other symptoms. This is called palliative or supportive care.
Comfort measures, safety measures, physical therapy, occupational therapy, and other treatments may improve the patient's quality of life. Some people may want to get legal advice to help them create advanced directives, such as a power of attorney.
You can ease the stress of illness by joining a support group where members share common experiences and problems. See: Cancer - support group
In general, the outcome is fairly poor. For many people with metastatic brain tumors, the cancer is not curable. It will eventually spread to other areas of the body. Death often occurs within 2 years.
Permanent, severe loss of nervous system function that gets worse over time
Calling your health care provider
Call your health care provider if you develop a persistent headache that is new or different for you.
Call your provider or go to the emergency room if you or someone else suddenly develops stupor, vision changes, or speech impairment, or has seizures that are new or different.
Maity A, Pruitt AA, Judy KD, Phillips PC, Lustig R. Cancer of the central nervous system. In: Abeloff MD, Armitage JO, Niederhuber JE, Kastan MB, McKenna WG, eds. Abeloff's Clinical Oncology. 4th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 70.
Deangelis LM. Tumors of the central nervous system and intracranial hypertension and hypotension. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 195.
Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington; and Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.