What is an astrocytoma?

Astrocytomas are tumors found in the central nervous system (CNS) that grow from star-shaped astrocyte cells. Astrocytes are glial cells (the type of cells that provide supportive tissue in the brain).

Some types of astrocytomas have small areas of infiltration, while others are more spread out. There are several types of astrocytomas, including:

  • Pilocytic: These tend to not spread and are considered to be noncancerous.
  • Diffuse: These grow slowly.
  • Anaplastic: These are rare but call for aggressive treatment.
  • Glioblastoma: This type grows aggressively and is the most common cancerous primary brain tumor.
  • Subependymal giant cell astrocytoma: This type is linked with tuberous sclerosis, a genetic condition.

Where are astrocytomas found most often?

Most of these tumors are found on the outer curve of the brain. Often, they are found at the top of the brain. Sometimes, they can develop at the base of the brain. Astrocytomas found in the brainstem or spinal cord occur less frequently.

Who is at risk for developing astrocytomas?

The average annual age-adjusted incidence rate for tumors of neuroepithelial tissue (which includes astrocytomas) is 6.6 per 100,000, according to figures from the Central Brain Tumor Registry of the United States in 2016.

Most cases of pilocytic astrocytomas are diagnosed by the age of 20. About 1,200 people younger than 19 in the United States will have an astrocytoma diagnosis. The 20-45 year age group accounts for about 60% of all low-grade astrocytoma diagnoses. A genetic component has been found in some cases. Males are only slightly more likely to develop astrocytomas than females.

Glioblastomas are often found when people are in their 50s and 60s. The number of U.S. diagnoses is estimated at 10,000 cases per year.

Symptoms and Causes

What are the causes of astrocytomas?

We do not know the exact cause of most astrocytomas. Therapeutic irradiation can lead to the development of astrocytomas. Other environmental exposures, though suspected, have not been shown to cause astrocytomas. Some studies have shown evidence of a genetic component in some cases.

What are the symptoms of astrocytomas?

Symptoms are related to the size and location of the astrocytoma. Common symptoms include:

Increased intracranial pressure may lead to abnormal reflexes or weakness on one side of the body.

Diagnosis and Tests

How are astrocytomas diagnosed?

Diagnosing astrocytomas can be difficult due to symptoms being similar to other neurological disorders. Some labs may be drawn, such as a complete blood count, basic metabolic profile, and blood clotting times, but are often normal. Radiological tests are used to diagnose astrocytomas.

What tests are used in diagnosing astrocytomas?

Magnetic resonance imaging (MRI) is the standard study. Computed tomography (CT scans) may be used if a patient cannot have an MRI. Other tests include:

A biopsy may be done to determine a definitive diagnosis.

Management and Treatment

How are astrocytomas managed and treated?

Decisions on the treatment of astrocytomas may be made with input from specialists, including neurologists, neurosurgeons, radiation oncologists and medical oncologists. Treatments include surgery, radiation therapy, chemotherapy and therapeutic electric fields.

Surgical treatments include biopsies, laser ablation and tumor resections. Drains may be put into place in order to decrease intracranial pressure. Radiation and/or chemotherapies are often prescribed for high-risk tumors. Tumor-treating electric fields may also be of benefit in some cases.

Your doctor may believe that the best treatment strategy is for patients to participate in clinical trials, when available. Staging of astrocytomas is not usually done because it is rare that they grow outside the brain. A person being treated for astrocytoma may also need physical therapy and/or occupational therapy.

Are there any restrictions for someone with an astrocytoma?

Restrictions will be based on the location of the astrocytoma and the extent of the symptoms. For example, if the astrocytomas cause seizures, driving may be prohibited. No other general activity restrictions are necessary, however.

What additional care may be needed?

Follow-up appointments with neurologists, medical oncologists, radiation oncologists and neurosurgeons may be required. Irradiation and chemotherapy may continue, and follow-up tests, such as additional MRIs are often needed.

Outlook / Prognosis

What is the prognosis for someone with an astrocytoma?

The prognosis may vary depending on the type and location of the astrocytoma. For example, patients with a glioblastoma may have a survival rate of less than one year, although some patients may live five years or more. Patients with a pilocytic astrocytoma may have a survival rate of about ten years. If remission is achieved, it can be permanent or temporary.

Last reviewed by a Cleveland Clinic medical professional on 09/05/2018.


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