Alternative names
Brain tumor - secondary; Brain tumor - metastatic; Cancer - brain tumor (secondary)

Definition

A metastatic brain tumor is a mass of cancerous cells in the brain that have spread from another part of the body.

The term “metastatic” means it has spread. The original source of the cancer is called the primary tumor. Cells from the primary tumor have traveled in the bloodstream (metastasized) and lodged in the brain.

Causes, incidence, and risk factors

Many tumor or cancer types can spread to the brain, the most common being lung cancer, breast cancer, melanoma, kidney cancer, bladder cancer, certain sarcomas, testicular and germ cell tumors, and a number of others. Some types of cancers only spread to the brain infrequently, such as colon cancer, or very rarely, such as prostate cancer.

Brain tumors can directly destroy brain cells, or they may indirectly damage cells by producing inflammation, compressing other parts of the brain as the tumor grows, inducing brain swelling, and causing increased pressure within the skull.

Metastatic brain tumors are classified depending on the exact site of the tumor within the brain, type of tissue involved, original location of the tumor, and other factors. Infrequently, a tumor can spread to the brain, yet the original site or location of the tumor is unknown. This is called cancer of unknown primary (CUP) origin.

Metastatic brain tumors occur in about one-fourth of all cancers that metastasize (spread through the body). They are much more common than primary brain tumors. They occur in approximately 10-30% of adult cancers.

Symptoms

 
• Headache - recent, persistent, and a new type for the person  
• Vomiting - with or without nausea  
• Personality changes  
• Emotional instability, rapid emotional changes  
• Memory loss, impaired judgment, calculating deficiencies  
• Seizures - new for the person  
• Vision changes - double vision, decreased vision  
• Changes in sensation of a body area  
• Weakness of a body area  
• Speech difficulties  
• Decreased coordination, clumsiness, falls  
• Fever (sometimes)  
• Lethargy  
• General ill feeling  
• Pupils of eyes are a different size

Note: The 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 reveals neurologic changes that are specific to the location of the tumor. Signs of increased pressure within the skull are also common. Some tumors may not show symptoms until they are very large. Then, they suddenly cause rapid decline in the person’s neurologic functioning.

The original (primary) tumor may already be known, or it may be discovered after an examination of tumor tissues from the brain indicates that it is a metastatic type of tumor.

 
• A head CT scan or MRI of the head can confirm the diagnosis of brain tumor and identifies the location of the tumor. MRI is usually more sensitive for finding tumors in the brain.  
• Cerebral angiography is occasionally performed. It may show a space-occupying mass, which may or may not be highly vascular (filled with blood vessels).  
• A chest x-ray; mammogram ; CT scans of the chest, abdomen and pelvis; and other tests are performed to look for the original site of the tumor.  
• An EEG may reveal abnormalities.  
• An examination of tissue removed from the tumor during surgery or CT scan-guided biopsy is used to confirm the exact type of tumor. If the primary tumor can be located outside of the brain, the primary tumor is usually biopsied rather than the brain tumor.  
• A lumbar puncture (spinal tap) is sometimes also performed to test the cerebral spinal fluid.

Treatment

Treatment depending on the size and type of the tumor, the initial site of the tumor, and the general health of the person. The goals of treatment may be relief of symptoms, improved functioning, or comfort.

Surgery may be used for metastatic brain tumors when there is a single lesion and when there is no cancer elsewhere in the body. Some may be completely removed. Tumors that are deep or that infiltrate brain tissue may be debulked (removing much of the tumor’s mass to reduce its size).

Surgery may reduce pressure and relieve symptoms in cases when the tumor cannot be removed. Radiation therapy may be advised for tumors that are sensitive to radiation.

Medications may include the following:

 
• Corticosteroids such as dexamethasone to reduce brain swelling  
• Osmotic diuretics such as urea or mannitol to reduce brain swelling  
• Anticonvulsants such as phenytoin to reduce seizures  
• Pain medication  
• Antacids or antihistamines to control stress ulcers  
• Chemotherapy

When multiple metastases (widespread cancer) are discovered, treatment may focus primarily on relief of pain and other symptoms.

Comfort measures, safety measures, physical therapy, occupational therapy, and other interventions may improve the patient’s quality of life. Legal advice may be helpful in forming advanced directives, such as power of attorney, in cases where continued physical or intellectual decline is likely.

Support Groups
For additional information, see cancer resources.

Expectations (prognosis)
In general, the probable outcome is fairly poor. For many people with metastatic brain tumors, the cancer spreads to other areas of the body. Death often occurs within 2 years.

Complications

 
• Brain herniation (fatal)  
• Permanent, progressive, profound neurologic losses  
• Loss of ability to interact  
• Loss of ability to function or care for self

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.

Medical Encyclopedia

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.