Childhood Cerebellar Astrocytoma

Childhood cerebellar astrocytoma is a disease in which benign (noncancer) or malignant (cancer) cells form in the tissues of the brain.
Astrocytomas are tumors that develop from brain cells called astrocytes. Cerebellar astrocytomas start in the cerebellum, which is located at the lower back of the brain. The cerebellum is the part of the brain that controls movement, balance, and posture.

About 15-25% of all childhood brain tumors are cerebellar astrocytomas. Although cancer is rare in children, brain tumors are the most common type of childhood cancer other than leukemia and lymphoma.

This summary refers to the treatment of primary brain tumors (tumors that begin in the brain). Treatment for metastatic brain tumors, which are secondary tumors formed by cancer cells that begin in other parts of the body and spread to the brain, is not discussed in this summary.

Brain tumors can occur in both children and adults; however, treatment for children may be different than treatment for adults. (Refer to the PDQ treatment summary on Adult Brain Tumors for more information.)

The cause of most childhood brain tumors is unknown.

The symptoms of childhood cerebellar astrocytoma vary and often depend on the child's age and where the tumor is located.
These symptoms may be caused by an astrocytoma or other conditions. A doctor should be consulted if any of the following problems occur:

• Loss of balance, difficulty walking, worsening handwriting, or slow speech.
• Morning headache or headache that goes away after vomiting.
• Nausea and vomiting.
• Unusual sleepiness or change in energy level.
• Change in personality or behavior.
• Unexplained weight loss or weight gain.

Tests that examine the brain and spinal cord are used to detect (find) childhood cerebellar astrocytoma.
The following tests and procedures may be used:

• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
• MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the brain and spinal cord. A substance called gadolinium is injected into the patient through a vein. The gadolinium collects around the cancer cells so they show up brighter in the picture. This procedure is also called nuclear magnetic resonance imaging (NMRI).

Childhood cerebellar astrocytoma is diagnosed and removed in surgery.
If a brain tumor is suspected, a biopsy is done by removing part of the skull and using a needle to remove a sample of the brain tissue. A pathologist views the tissue under a microscope to look for cancer cells. If cancer cells are found, the doctor will remove as much tumor as safely possible during the same surgery.

The most important factors that affect prognosis (chance of recovery) are thought to be the type of astrocytoma and whether cancer cells remain after surgery. Treatment options depend on whether cancer cells remain after surgery or have spread to other parts of the brain, the location of the tumor, and the child's age.

Stages of Childhood Cerebellar Astrocytoma
After the childhood cerebellar astrocytoma has been removed, tests are done to find out if there is tumor remaining. The extent or spread of cancer is usually described as stages. For childhood cerebellar astrocytoma, the grade of the tumor is used instead of stages. The grade of the tumor refers to how abnormal the cancer cells look under a microscope and how quickly the tumor is likely to grow and spread. It is important to know the grade of the tumor and if there were any cancer cells remaining after surgery in order to plan the best treatment.

There are two grades for childhood cerebellar astrocytoma:

• Grade I pilocytic tumors are very slow-growing and rarely spread. These tumors form inside cysts.
• Grade II diffuse or fibrillary tumors spread slowly within the brain.

The following procedure may be used to determine if any cancer cells remain in the brain after surgery:

• MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the brain and spinal cord. A substance called gadolinium is injected into the patient through a vein. The gadolinium collects around the cancer cells so they show up brighter in the picture. This procedure is also called nuclear magnetic resonance imaging (NMRI).

Cerebellar astrocytomas do not usually spread from the cerebellum to other parts of the brain or body.

Recurrent Childhood Cerebellar Astrocytoma
Recurrent childhood cerebellar astrocytoma is a tumor that has recurred (come back) after it has been treated. Childhood cerebellar astrocytoma may recur many years after initial treatment. The tumor may recur at the same place in the brain or in other parts of the central nervous system (brain and spinal cord), especially if the original tumor was a diffuse or fibrillary tumor.

There are different types of treatment for children with cerebellar astrocytoma.
Different types of treatment are available for children with cerebellar astrocytoma. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the "standard" treatment, the new treatment may become the standard treatment.

Because cancer in children is rare, taking part in a clinical trial should be considered. Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Cancer.gov Web site. Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.

Children with cerebellar astrocytoma should have their treatment planned by a team of doctors with expertise in treating childhood brain tumors.
Your child's treatment will be overseen by a pediatric oncologist, a doctor who specializes in treating children with cancer. The pediatric oncologist may refer you to other pediatric doctors who have experience and expertise in treating children with brain tumors and who specialize in certain areas of medicine. These may include the following specialists:

• Neurosurgeon.
• Neurologist.
• Neuropathologist.
• Neuroradiologist.
• Rehabilitation specialist.
• Radiation oncologist.
• Medical oncologist.
• Endocrinologist.
• Psychologist.

Three types of standard treatment are used:

Surgery
Surgery is used to diagnose and treat childhood cerebellar astrocytoma.

Radiation therapy
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Chemotherapy
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly in the spinal column, a body cavity such as the abdomen, or an organ, the drugs mainly affect cancer cells in those areas. The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Untreated Childhood Cerebellar Astrocytoma
Untreated childhood cerebellar astrocytoma is a tumor for which no treatment has been given. The child may have received drugs or treatment to relieve symptoms caused by the tumor.

Initial treatment for childhood cerebellar astrocytoma is usually surgery. When the tumor is completely removed by surgery, more treatment may not be needed and the child is closely observed for symptoms to appear or change. This is also called watchful waiting.

If cancer cells remain after surgery, treatment depends on the location of the remaining cancer cells and the age of the child. Treatment may include the following:

• Watchful waiting.
• Another surgery to remove the tumor.
• Radiation therapy.
• Chemotherapy.

Recurrent Childhood Cerebellar Astrocytoma
Treatment of recurrent childhood cerebellar astrocytoma may include the following:

• Surgery.
• Radiation therapy.
• Chemotherapy.
• A clinical trial of new anticancer drugs.

Source: National Institutes of Health; National Cancer Institute