Astrocytomas are tumors that typically form in your brain, but can develop in your spinal cord as well. Most astrocytomas develop randomly. Treatment varies depending on the type, but surgery is usually the first option.


What is astrocytoma?

Astrocytomas are tumors that develop in your central nervous system (CNS) that grow from star-shaped astrocyte cells. They usually develop in your brain but can develop in your spinal cord as well. Astrocytomas can be benign (noncancerous) or malignant (cancerous).

Astrocytes are glial cells (the type of cells that provide supportive tissue in your brain). Other glial cells include oligodendrocytes and ependymal cells. Astrocytoma is the most common glioma. A glioma is a tumor that forms when glial cells grow out of control.

Healthcare providers use grades to describe different types of astrocytomas. They don’t use a staging system as they do for many other types of cancer.


Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

What are the types of astrocytoma?

Astrocytomas may be cancerous or noncancerous. The World Health Organization (WHO) categorizes astrocytomas into four grades. The grades depend on how fast astrocytomas grow and the likelihood that they’ll spread to (infiltrate) nearby brain tissue. Grade 1 astrocytomas are the mildest, while grade 4 astrocytomas are the most aggressive.

Noncancerous astrocytomas

Grade 1 astrocytomas, which are noncancerous, include:

  • Pilocytic astrocytoma: This is a slow-growing tumor that doesn’t tend to spread. It’s the most common grade 1 astrocytoma. It’s benign and doesn’t require chemotherapy or radiation therapy after it’s surgically removed. Pilocytic astrocytomas most often develop in your cerebellum.
  • Pleomorphic xanthoastrocytoma: This tumor usually grows slowly and most often develops in your temporal lobe. It often causes seizures. Surgery usually cures this type of brain tumor.
  • Subependymal giant cell astrocytoma (SEGA): This tumor mainly develops in children who have tuberous sclerosis, a genetic condition. It grows inside ventricles, which are fluid-filled spaces deep in your brain. Surgery usually cures it.

Cancerous astrocytomas

Cancerous astrocytomas include:

  • Grade 2 astrocytomas: These astrocytomas tend to spread to nearby brain tissue. Because of this, surgery alone might not be enough to treat them.
  • Grade 3 astrocytomas: These astrocytomas are more aggressive than grade 2 astrocytomas and often present as a progression from grade 2 astrocytomas. Surgery alone never cures these tumors. They require radiation and almost always require chemotherapy.
  • Glioblastomas: These are grade 4 astrocytomas. They’re the most common form of astrocytoma and the most aggressive — they grow and spread rapidly. They can either present as a cancerous progression from a previously existing lower-grade astrocytoma (10% of cases) or begin as a grade 4 tumor (90% of cases).

Who does astrocytoma affect?

Astrocytomas can affect anyone, but different grades tend to affect people at different ages:

  • Grade 1 astrocytomas most often affect children and teens.
  • Astrocytomas, grade 2 most often affect adults between 20 and 60.
  • Astrocytomas, grade 3 most often affect adults between 30 and 60.
  • Glioblastoma (grade 4 astrocytoma) most often affects adults between 50 and 80.

Grade 3 and 4 astrocytomas are more likely to affect adults assigned male at birth than adults assigned female at birth.


How common is astrocytoma?

Different grades of astrocytoma are more common than others:

  • Grade 1 astrocytomas account for 2% of all brain tumors.
  • Grade 2 astrocytomas account for 2% to 5% of all brain tumors.
  • Grade 3 astrocytomas account for 4% of all brain tumors.
  • Grade 4 astrocytomas (glioblastomas) account for 24% of all brain tumors.

In adults, glioblastoma (grade 4 astrocytoma) is the most common type of brain cancer.

Symptoms and Causes

What are the symptoms of astrocytoma?

The symptoms of astrocytoma can vary based on its size and location. Common symptoms include:

See a healthcare provider as soon as possible if you have these symptoms.


What causes astrocytoma?

Researchers don’t know the exact cause of most astrocytomas. The majority of these tumors are sporadic, meaning that they happen randomly. So far, researchers have only identified two known risk factors for astrocytomas: radiation exposure and genetics.

However, recent studies have revealed that a mutation (change) in the IDH1 gene contributes significantly to the development of low-grade astrocytomas. This gene helps provide energy to your cells. Its mutation results in the production of a chemical called 2-HG, which, over time, builds up inside healthy astrocytes. This buildup causes the cells to become abnormal, causing astrocytomas.

Radiation exposure and astrocytomas

Exposure to ionizing radiation, such as from radiation therapy, increases your risk of developing astrocytoma.

For example, children who receive prophylactic (preventive) radiation for acute lymphocytic leukemia (ALL) may be 22 times more likely to develop a central nervous system tumor, such as astrocytoma, within about five to 10 years.

Genetics and astrocytomas

The following rare genetic conditions are associated with the development of astrocytomas:

  • Li-Fraumeni syndrome: This condition happens when something changes in your TP53 gene. People who have Li-Fraumeni syndrome have a 90% chance of developing one or more types of cancer in their lifetimes, which could include astrocytoma.
  • Neurofibromatosis type 1 (NF1): This condition causes abnormal increases in cell growth due to a mutation in a gene that’s supposed to suppress tumor growth. People with NF1 can develop early-onset astrocytomas, peripheral nerve tumors and spots on their skin called café-au-lait spots.
  • Tuberous sclerosis: This condition causes a variety of medical issues, including epilepsy, developmental delay and tumors throughout your body. Tuberous sclerosis is caused by mutations in two genes: TSC1 and TSC2. Subependymal giant cell astrocytomas (SEGAs) typically only develop in people with tuberous sclerosis.
  • Turcot syndrome: This condition results when there are mutations in several genes that suppress tumor growth. Turcot syndrome often involves growths (polyps) in your intestinal tract and one or more brain or spinal cord tumors, such as astrocytoma.

Diagnosis and Tests

How are astrocytomas diagnosed?

It can be difficult for healthcare providers to detect or suspect astrocytomas, as their symptoms are similar to other neurological conditions.

Regardless, your provider will ask about your symptoms and medical history. They’ll likely perform a neurological exam. This can help determine where in your brain or spinal cord the issue may be.

Your provider may order a brain imaging test. Magnetic resonance imaging (MRI) is the best imaging test for finding and diagnosing astrocytoma. If you’re unable to have an MRI scan due to having a pacemaker or joint implant, a computed tomography (CT scan) is the next best option.

If something abnormal appears on the brain imaging test, your provider will most likely recommend a biopsy or resection (tumor removal) to determine the diagnosis.

Management and Treatment

Is astrocytoma cancer curable?

Surgery can cure most grade 1 astrocytomas if your neurosurgeon can safely remove the entire tumor. Very rarely, surgery may also cure some grade 2 astrocytomas.

There’s no cure for grade 3 and grade 4 astrocytomas, as they grow and spread quickly. But radiation therapy and some medications can help slow their growth and help with symptoms.

How is astrocytoma treated?

Astrocytoma treatment depends on several factors, including:

  • The tumor’s location, size and type.
  • Your age.
  • Your overall health.

Several specialists will work together to determine the best treatment plan for you. They may include:

The main forms of treatment for astrocytomas are:

There may also be clinical trials that you can participate in.

Surgery for astrocytomas

Surgery is the first step in the treatment of astrocytomas. It provides three significant benefits:

  • It allows your healthcare team to get tissue from the tumor to view it under a microscope to determine the exact type.
  • Providers can perform additional tests on the tumor to look for proteins and mutations that certain medications could target.
  • It offers the possibility to remove as much of the tumor as possible. This can help relieve pressure and prevent other issues in your brain and skull.

Since grade 1 astrocytomas grow slowly and don’t spread to other areas of your brain, surgery is usually all it takes to treat them.

Adjuvant therapies for astrocytomas

Adjuvant therapy, sometimes called helper therapy, targets cancer cells that primary treatment didn’t destroy. In the case of astrocytomas, surgery is the primary treatment.

Grade 3 and grade 4 astrocytomas always require treatments other than surgery alone. Grade 2 astrocytomas may sometimes require adjuvant therapy.

Adjuvant therapies for astrocytomas include:

  • Chemotherapy with temozolomide (TMZ): Chemotherapy involves medications that destroy cancer cells and/or prevent them from multiplying. Temozolomide (TMZ) is a drug that works by changing the DNA of tumor cells and, thus, causing the cells to die. TMZ is a first-line adjuvant therapy treatment for every grade 3 and grade 4 astrocytoma. Providers sometimes also prescribe it for grade 2 astrocytomas.
  • Radiation therapy: This treatment uses radiation (usually high-powered X-rays) to kill cancer cells. It’s typically very effective in helping treat astrocytomas.
  • Bevacizumab: This is an injected medication that prevents blood vessels from helping the tumor to grow. The U.S. Food and Drug Administration (FDA) has approved bevacizumab for recurrent glioblastomas. It helps reduce swelling and can help improve symptoms.
  • Tumor-treating fields: This is a special device that produces electrical fields that can delay tumor growth. You wear it like a helmet. Healthcare providers may recommend this treatment for newly diagnosed and recurrent glioblastomas.


Can I prevent developing astrocytoma?

There’s nothing you can do to prevent developing astrocytoma. Most cases happen randomly.

If you have a genetic condition that puts you at higher risk for astrocytoma, be sure to see your healthcare team regularly so they can monitor you for signs of astrocytoma. The earlier they can catch it, the better.

Outlook / Prognosis

What is the prognosis of astrocytoma?

The prognosis (outlook) of astrocytoma depends on several factors, including:

  • Tumor grade: The prognosis generally gets worse as the grade increases.
  • How much of the tumor can be surgically removed: While grade 1 astrocytoma is usually cured with surgery alone, it’s impossible to completely remove grade 2 through 4 astrocytomas. However, the more tissue the neurosurgeon can remove, the better the survival rate.
  • Use of adjuvant therapy: Adjuvant therapy, such as chemotherapy and radiation therapy, can help minimize symptoms and increase the survival rate.
  • Age: In general, young age is associated with longer survival.
  • Mental status: Minimal symptoms and normal neurological function are associated with longer survival.

Your healthcare team will be able to give you more accurate information about what you can expect. Don’t be afraid to ask them questions.

What is the survival rate of astrocytoma?

The average survival rate varies depending on the grade of astrocytoma:

  • Grade 1 (pilocytic astrocytomas): More than 10 years.
  • Grade 2 astrocytomas: More than five years.
  • Grade 2 astrocytomas: About two to five years.
  • Grade IV (glioblastomas): About a year.

It’s important to remember that these are just averages based on large groups of people who’ve had astrocytoma. Your healthcare team can provide more detailed information about survival rates based on your unique situation.

Living With

When should I see my healthcare provider about astrocytoma?

You may need follow-up appointments with neurologists, oncologists and neurosurgeons to make sure your treatment has worked or is continuing to work.

Contact your healthcare provider as soon as possible if you develop new or worsening symptoms, such as:

What questions should I ask my doctor?

It may be helpful to ask your healthcare team the following questions:

  • Why did I get astrocytoma?
  • What kind of astrocytoma do I have?
  • What’s the best treatment for me?
  • What clinical trials am I eligible for?
  • What are the treatment risks and side effects?
  • What type of follow-up care do I need after treatment?
  • What are the chances that the cancer will come back or spread after treatment?
  • What signs of tumor growth should I look for?
  • What signs of treatment complications should I look for?
  • Are my family members at risk of developing astrocytoma?

Additional Common Questions

What is the difference between astrocytoma and glioblastoma?

Glioblastoma is a type of astrocytoma — a grade 4 astrocytoma, specifically. Glioblastoma is an aggressive cancerous tumor that grows and spreads quickly. It’s the most common cancerous primary brain tumor.

Is astrocytoma malignant or benign?

There are several types of astrocytoma tumors — some are benign and some are malignant. Grade 1 astrocytomas are benign (noncancerous). Grades 2 through 4 are malignant (cancerous).

A note from Cleveland Clinic

Learning you have a tumor in your brain can be scary and stressful. Astrocytomas can vary in severity depending on the grade — some are benign and some are cancerous. Know that your healthcare team will develop an individualized and thorough treatment plan to help treat the astrocytoma and improve your quality of life.

Medically Reviewed

Last reviewed on 03/31/2023.

Learn more about our editorial process.

Appointments 866.588.2264