Definition of brain tumor: The growth of abnormal cells in the tissues of the brain. Brain tumors can be benign (non-cancerous) or malignant (cancerous).

Estimated new cases and deaths from brain and other nervous system tumors in the United States in 2008:

New Cases: 21,810
Deaths: 13,070

Primary and Secondary Brain Tumors

A tumor that begins in the brain is called a primary brain tumor. In children, most brain tumors are primary tumors. In adults, most tumors in the brain have spread there from the lung, breast, or other parts of the body. When this happens, the disease is not brain cancer. The tumor in the brain is a secondary tumor. It is named for the organ or the tissue in which it began.

Treatment for secondary brain tumors depends on where the cancer started and the extent of the disease.

Malignant brain tumors contain cancer cells:

• Malignant brain tumors are generally more serious and often are life threatening.

• They are likely to grow rapidly and crowd or invade the surrounding healthy brain tissue.

• Very rarely, cancer cells may break away from a malignant brain tumor and spread to other parts of the brain, to the spinal cord, or even to other parts of the body. The spread of cancer is called metastasis.

• Sometimes, a malignant tumor does not extend into healthy tissue. The tumor may be contained within a layer of tissue. Or the bones of the skull or another structure in the head may confine it. This kind of tumor is called encapsulated.

The most common primary brain tumors are gliomas. They begin in glial cells. There are many types of gliomas:

• Astrocytoma—The tumor arises from star-shaped glial cells called astrocytes. In adults, astrocytomas most often arise in the cerebrum. In children, they occur in the brain stem, the cerebrum, and the cerebellum. A grade III astrocytoma is sometimes called an anaplastic astrocytoma. A grade IV astrocytoma is usually called a glioblastoma multiforme.

• Brain stem glioma—The tumor occurs in the lowest part of the brain. Brain stem gliomas most often are diagnosed in young children and middle-aged adults.

• Ependymoma—The tumor arises from cells that line the ventricles or the central canal of the spinal cord. They are most commonly found in children and young adults.

• Oligodendroglioma—This rare tumor arises from cells that make the fatty substance that covers and protects nerves. These tumors usually occur in the cerebrum. They grow slowly and usually do not spread into surrounding brain tissue. They are most common in middle-aged adults.

Symptoms

The symptoms of gliomas or brain tumors depend on tumor size, type, and location. Symptoms may be caused when a tumor presses on a nerve or damages a certain area of the brain. They also may be caused when the brain swells or fluid builds up within the skull.

These are the most common symptoms of gliomas or brain tumors:

• Headaches (usually worse in the morning)

• Nausea or vomiting

• Changes in speech, vision, or hearing

• Problems balancing or walking

• Changes in mood, personality, or ability to concentrate

• Problems with memory

• Muscle jerking or twitching (seizures or convulsions)

• Numbness or tingling in the arms or legs

These symptoms are not sure signs of a benign or malignant glioma or brain tumor. Other conditions also could cause these problems. Anyone with these symptoms should see a doctor as soon as possible. Only a doctor can diagnose and treat the problem.

Methods of Treatment for Malignat Glioma and Other Brain Tumors

People with brain tumors have several treatment options. Depending on the tumor type and stage, patients may be treated with surgery, radiation therapy, or chemotherapy. Some patients receive a combination of treatments.

In addition, at any stage of disease, patients may have treatment to control pain and other symptoms of the cancer, to relieve the side effects of therapy, and to ease emotional problems. This kind of treatment is called symptom management, supportive care, or palliative care.

The doctor is the best person to describe the treatment choices and discuss the expected results.

A patient may want to talk to the doctor about taking part in a clinical trial, which is a research study of new treatment methods.

Surgery is the usual treatment for malignant glioma and most brain tumors. Surgery to open the skull is called a craniotomy. It is performed under general anesthesia. Before surgery begins, the scalp is shaved. The surgeon then makes an incision in the scalp and uses a special type of saw to remove a piece of bone from the skull. After removing part or all of the tumor, the surgeon covers the opening in the skull with that piece of bone or with a piece of metal or fabric. The surgeon then closes the incision in the scalp.

Sometimes surgery is not possible. If the tumor is in the brain stem or certain other areas, the surgeon may not be able to remove the tumor without damaging normal brain tissue. Patients who cannot have surgery may receive radiation or other treatment.

Radiation therapy (also called radiotherapy) uses high-energy rays to kill malignant glioma and other brain tumor cells. The radiation may come from x-rays, gamma rays, or protons. A large machine aims radiation at the tumor and the tissue close to it. Sometimes the radiation may be directed to the entire brain or to the spinal cord.

Radiation therapy usually follows surgery. The radiation kills tumor cells that may remain in the area. Sometimes, patients who cannot have surgery have radiation therapy instead.

The patient goes to a hospital or clinic for radiation therapy. The treatment schedule depends on the type and size of the tumor and the age of the patient. Each treatment lasts only a few minutes.

Doctors take steps to protect the healthy tissue around the brain tumor:

• Fractionation—Radiation therapy usually is given five days a week for several weeks. Giving the total dose of radiation over an extended period helps to protect healthy tissue in the area of the tumor.

• Hyperfractionation—The patient gets smaller doses of radiation two or three times a day instead of a larger amount once a day.

• Stereotactic radiation therapy—Narrow beams of radiation are directed at the glioma or brain tumor from different angles. For this procedure, the patient wears a rigid head frame. An MRI or CT scan creates pictures of the tumor's exact location. The doctor uses a computer to decide on the dose of radiation needed, as well as the sizes and angles of the radiation beams. The therapy may be given during a single visit or over several visits.

• 3-dimensional conformal radiation therapy—A computer creates a 3-dimensional image of the brain tumor and nearby brain tissue. The doctor aims multiple radiation beams to the exact shape of the brain tumor. The precise focus of the radiation beams protects normal brain tissue.

• Proton beam radiation therapy—The source of radiation is protons rather than x-rays. The doctor aims the proton beams at the glioma or brain tumor. Protons can pass through healthy tissue without damaging it.

Chemotherapy, the use of drugs to kill cancer cells, is sometimes used to treat gliomas or brain tumors. The drugs may be given by mouth or by injection. Either way, the drugs enter the bloodstream and travel throughout the body. The drugs are usually given in cycles so that a recovery period follows each treatment period.

Chemotherapy may be given in an outpatient part of the hospital, at the doctor's office, or at home. Rarely, the patient may need to stay in the hospital.

Children are more likely than adults to have chemotherapy. However, adults may have chemotherapy after surgery and radiation therapy.

For some patients with recurrent cancer of the brain, the surgeon removes the glioma or brain tumor and implants several wafers that contain chemotherapy. Each wafer is about the size of a dime. Over several weeks, the wafers dissolve, releasing the drug into the brain. The drug kills cancer cells.

 

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