Written by Glenn Rosenberg
Wednesday, 07 October 2009
Brain tumors are masses of cells that grow within the brain. Slow-growing cells may form a benign, or noncancerous, tumor. Abnormal cells that grow rapidly may form a cancerous tumor.
What is going on in the body?
The brain is tightly contained within the closed cavity of the skull. There is very little extra room within the bony skull cavity. A growing brain tumorcan destroy brain cells directly. Or, it may put pressure on the nearby tissue and destroy cells. These effects can occur with either a benign or a cancerous tumor.
A brain tumor that starts within the brain is known as a primary brain tumor. Often, a brain tumor grows from cells that metastasize, or spread, from a cancer elsewhere in the body. Some of the cancers that often metastasize the brain are as follows:
- breast cancer
- colorectal cancer
- kidney cancer
- lung cancer
- melanoma, a skin cancer
- testicular cancer
What are the causes and risks of the condition?
The people most at risk for brain tumors include:
- children, especially those who have cancer elsewhere in the body
- elderly people, especially those at risk for cancer in other areas of the body
- people who have been exposed to pesticides, industrial solvents, and other chemicals
- people who have certain genetic alterations
- people who have certain inherited diseases, including neurofibromatosis
- people who have received X-ray exposure to the head
- people who have weak immune systems, such as those who have immunodeficiency disorders
Many other risk factors have been reported to increase the risk of brain tumors. Research findings have been either unconvincing or conflicting. Additional factors that need further study include:
- cellular telephones
- hair dye
- head injury
- household appliances, such as microwaves
- nutritional factors
- power lines
- viruses and other biological agents
What are the treatments for the condition?
Medicines may be used to reduce swelling around the tumor. These include corticosteroids, such as dexamethasone. Furosemide or mannitol may also be used. A craniotomy, or brain surgery, is usually done to reduce intracranial pressure. It is also used to make the correct diagnosis. A craniotomy is especially important in the case of noncancerous brain tumors. These usually do not respond to radiation therapy and chemotherapy. It is best to remove them completely.
Cancerous brain tumors are generally removed with a craniotomy. Radiation therapy and chemotherapy after surgery will help increase the person's chance of survival.
Physical therapy, occupational therapy, and speech therapy may be helpful to improve or correct function after the tumor has been treated.
What are the side effects of the treatments?
The side effects of steroids, such as weight gain and increased risk of infection, may occur with a long period of treatment. Radiation therapy will usually produce some hair loss. Chemotherapy can cause nausea, vomiting, and a low red blood cell count, or anemia.
What happens after treatment for the condition?
A person's progress depends on the area of the brain that was affected by the tumor and the treatment used. Some people have ongoing disabilities. These may include impaired speech, as well as cognition and mobility impairments. Others recover completely.