Astrocytoma

Overview

Astrocytoma is a type of brain tumor or spinal cord tumor. It starts in cells called astrocytes. These star-shaped cells help keep nerve cells healthy and working as they should.

Astrocytoma symptoms depend on where the tumor grows. A brain astrocytoma can cause headaches, seizures, nausea, or changes in mood or behavior. A spinal cord astrocytoma may cause weakness or trouble moving the arms or legs.

Astrocytomas can behave in different ways. Some are slower growing and considered less aggressive, while others grow and spread more quickly. Doctors often test the tumor's genes or molecular features to help choose the best treatment.

Astrocytoma is part of a larger group of brain tumors called gliomas. These tumors start in cells that help support nerve cells. Astrocytomas are graded 1 to 4 based on how fast they grow. Grade 4 astrocytoma, also called glioblastoma, grows the fastest and is the most aggressive. Lower grade astrocytomas, grades 1 to 3, usually grow more slowly. They often have a better outlook than glioblastoma. Treatment and prognosis depend on the tumor's grade, size, location and molecular features.

Symptoms

Astrocytoma symptoms often start out as mild. Symptoms depend on where the tumor is in the brain or spinal cord. These brain tumor symptoms can change as the tumor grows. Early symptoms come from local irritation of the nearby brain tissue. Later symptoms happen as the brain tumor grows and pressure builds in the brain or spinal canal.

Low-grade astrocytomas can grow larger before causing symptoms, while high-grade brain tumors tend to cause symptoms sooner.

Early symptoms of astrocytoma

• New seizures, which are often the first sign in slow-growing tumors.
• Subtle changes in thinking, mood or memory.
• Mild headaches.
• Difficulty finding the right words to say.
• Changes in vision.
• Clumsiness on one side of the body.
• Pain in the neck or back that begins slowly.
• Tingling or numbness that travels into an arm or leg.

Later symptoms of astrocytoma as the tumor grows

• Headaches that get worse, especially in the morning or with coughing or straining.
• Nausea and vomiting, which can happen as a result of increased pressure.
• Increasing weakness.
• Speech or vision troubles.
• Changes in memory, thinking or concentration, called cognitive decline.
• Worsening balance.
• Bowel or bladder changes.

Back and lower part of brain

• Trouble with balance and coordination such as stumbling or shaky movements.
• Headache, nausea and vomiting from pressure in the brain.

Brainstem

• Double vision or other eye movement issues.
• Facial weakness or lack of feeling in the face.
• Difficulty speaking or swallowing.
• Difficulty with walking and balance.
• Weakness.

Spinal cord

• Back or neck pain that slowly gets worse.
• Pain that spreads into an arm or leg.
• Numbness and tingling.
• Weakness.
• Poor balance, falls and unsteadiness when walking.
• Bowel or bladder changes that may occur later.

These symptoms aren't necessarily specific to astrocytoma but can happen with many types of brain tumors. New symptoms or symptoms that get worse should be checked by your healthcare professional. These symptoms include a first-time seizure, vision changes, speech trouble, one-sided weakness or headaches that are worse in the morning.

Can swelling, called edema, around the tumor worsen symptoms?

Yes. Swelling of brain tissue around the tumor is called peritumoral edema. It can make symptoms worse or cause new symptoms to appear. These symptoms may include headaches, weakness, speech trouble or vision changes. The swelling increases pressure inside the skull and can stretch or irritate nearby brain pathways. This may worsen common symptoms. Short courses of steroid medicines may be used to reduce swelling and relieve symptoms.

Edema is more common in high-grade astrocytomas and contributes to symptoms even when the tumor itself is not very large.

How do children's symptoms of pilocytic astrocytoma differ from adult symptoms?

Pilocytic astrocytomas are a type of astrocytoma that are more common in children and teens. Adults can have these tumors, but it is rare. Because pilocytic astrocytomas grow slowly, symptoms often develop gradually over weeks or months.

Children may have:

• Headaches, especially in the morning.
• Balance problems or clumsiness if the tumor is in the cerebellum.
• Nausea, vomiting or irritability from pressure in the brain.
• Vision problems if the tumor affects the optic pathway.

In very young children, parents may notice changes in coordination, school performance or behavior.

In adults, astrocytomas are more likely to develop in a different part of the brain. They may cause new seizures, speech issues, or changes in thinking or personality as early symptoms.

Astrocytoma grading system

Astrocytomas are sorted into grades depending on how their cells appear and act under a microscope. The World Health Organization (WHO) created this grading system to help predict how quickly the tumor might grow or spread and to guide treatment decisions.

Circumscribed versus diffuse tumors

Some astrocytomas are called circumscribed, and others are called diffuse. Circumscribed means the tumor is well defined and localized. Diffuse astrocytomas spread into nearby brain tissue. Circumscribed defines the growth pattern and the category of the tumor, but not the grade. Pilocytic and pleomorphic xanthoastrocytoma (PXA) are circumscribed tumors. These are grouped separately from diffuse astrocytomas.

IDH tumors

IDH is a gene found in cells. There are two: IDH1 and IDH2. When a tumor is IDH wild type, it means the IDH gene looks healthy and there's no change to the IDH gene in the tumor cells. Glioblastoma is an IDH wild-type tumor.

When a tumor is IDH mutant, there is a change in the IDH1 or IDH2 gene. In the current WHO system, if lab tests show an IDH change, the tumor is named astrocytoma, IDH mutant. After naming the type, a grade is assigned — 2, 3 or 4 — based on how fast it's likely to grow. IDH testing helps the healthcare team classify the tumor and predict how it may behave.

When to see a doctor

Make an appointment with a healthcare professional if you have ongoing symptoms that worry you.

Causes

The exact cause of astrocytoma, a type of brain or spinal cord tumor, often isn't known. It starts when brain or spinal cord cells called astrocytes begin to grow and divide in an unusual and uncontrolled way. Astrocytes usually support and protect cells in the brain and spinal cord.

Astrocytoma happens when astrocytes develop changes in their DNA. A cell's DNA holds the instructions that tell the cell what to do. In healthy cells, the DNA gives instructions to grow and multiply at a set rate. The instructions tell the cells to die at a set time.

In tumor cells, the changes in the DNA give different instructions. These gene changes are called mutations. They likely cause astrocytoma by affecting how cells control growth and repair damage. The changed genes make the cells divide when they shouldn't and live longer than they should. This causes too many cells to group together and form a tumor.

As the tumor grows, it can press on nearby areas of the brain or spinal cord. Sometimes the DNA changes turn the tumor cells into cancer cells. Cancer cells can invade and destroy healthy body tissue.

Scientists have found that certain gene changes inside the tumor drive this unhealthy growth of astrocytoma cells:

• IDH1 and IDH2 gene changes affect how tumor cells make and use energy. They are common in many low-grade astrocytomas.
• TP53 and ATRX gene changes affect how cells repair DNA and manage cell growth.
• MGMT gene silencing affects how tumor cells repair DNA damage and can affect how well treatment works.
• In children, BRAF gene changes are often seen in slow-growing brain tumors called pilocytic astrocytomas. These gene changes develop inside the tumor and are not usually passed down in families.

Pilocytic astrocytoma tumors happen when a growth signal in the cell gets stuck "on." This causes the cells to grow slowly in one spot. High-grade astrocytomas develop after many harmful DNA changes build up. This makes the cells grow quickly and spread into nearby brain tissue.

Risk factors

Astrocytoma risk factors include:

• History of high-dose ionizing radiation therapy to the head or neck. If you had high-dose radiation for another cancer, your risk may be higher. This is especially true if the radiation was near the head or neck and especially during childhood.
• Age. Astrocytomas can occur in both children and adults. Children more often have low-grade tumors, which tend to grow slowly. Adults more often have high-grade tumors, which grow more quickly and act more aggressively. Most high-grade astrocytomas are diagnosed after age 40.
• Inherited conditions. Certain rare conditions that run in families, such as neurofibromatosis type 1 (NF1), Lynch syndrome, Turcot syndrome and tuberous sclerosis may increase risk.

Could lifestyle or the environment cause astrocytoma?

There's no proven link between lifestyle factors, such as diet, exercise or smoking, and astrocytoma. Other suspected environmental risks, such as chemical exposures or cellphone use, have not been shown to cause astrocytoma. Most cases appear by chance, without a clear outside trigger.

There is no known way to prevent astrocytoma.

Complications

Astrocytomas can cause complications as the tumor grows or as a result of treatment. Possible astrocytoma complications include:

• Neurological issues. The tumor may press on parts of the brain or spinal cord. This can lead to headaches, seizures, trouble speaking, weakness or difficulty walking.
• Tumor recurrence. Even after treatment, astrocytomas may come back, especially if they are high grade or could not be fully removed.
• Treatment risks and side effects. Surgery, radiation and chemotherapy sometimes can cause side effects such as trouble with memory or thinking, seizures, headaches, nausea, or fatigue. In some cases, treatment may damage healthy brain tissue.

Your care team works with you to help manage these issues and support your quality of life.

Diagnosis

Astrocytoma is diagnosed using several tests and procedures. They include a neurological exam, imaging scans and a biopsy. These help the healthcare team confirm the type, grade and genetic features of the tumor.

Neurological exam

During this exam, your healthcare team asks about your symptoms. You may have tests to check your vision, hearing, balance, coordination, strength and reflexes. Trouble in one or more of these areas may help show the part of your brain affected by a brain tumor.

Removing a sample of tissue for testing

A biopsy is a procedure to take a sample of tissue from the tumor for testing. After imaging shows a possible tumor, a biopsy is needed to confirm the diagnosis and learn more about the tumor's molecular features. The sample often is taken during surgery to remove the astrocytoma.

If the astrocytoma is in a spot that's hard to reach with surgical tools, a needle might be used to get the sample. The tissue goes to a lab for review under a microscope. Tests can determine the types of cells and how quickly they grow. This is called molecular testing. During this testing, doctors also study the tumor's genes and molecules. Types of molecular testing include:

• IDH (isocitrate dehydrogenase) testing. This test looks for a change in the IDH1 or IDH2 gene. Tumors with this change usually grow more slowly and respond better to treatment.
• MGMT (O-6-methylguanine-DNA methyltransferase) promoter methylation. This test looks at whether this DNA repair gene is "turned off." If it is, the tumor may respond better to chemotherapy with the medicine temozolomide.
• 1p/19q codeletion. This tests whether parts of chromosomes 1 and 19 are missing. This helps confirm whether the tumor is an oligodendroglioma. This type of tumor often responds well to radiation and chemotherapy.

A biopsy is the only way to confirm the diagnosis of astrocytoma and find out what type and grade it is. Testing done on the biopsy sample can help predict how the tumor will grow and behave, and which treatments are most likely to be effective.

Together, these tests help the care team confirm the exact tumor type and predict how it will behave, and choose the most effective treatment plan.

Can spinal taps or blood tests detect astrocytoma?

No, spinal taps and blood tests usually can't detect an astrocytoma. Astrocytomas form inside the brain or spinal cord. Routine blood work or spinal fluid tests don't show clear signs of these tumors.

In some rare cases, a healthcare professional may do a spinal tap (lumbar puncture) to check for tumor cells in the cerebrospinal fluid (CSF). This may be done if there's concern the tumor has spread within the brain or spinal canal. But this test is used only in special situations after imaging suggests the tumor has spread.

Blood tests are mainly used to check general health and to see how the body is handling treatment, not to find the tumor itself.

Imaging tests

To see the tumor more clearly, your care team may use imaging tests. A brain MRI is often used to diagnose brain tumors. Sometimes special types of MRI, such as functional MRI, perfusion MRI, or MR spectroscopy, are used. Other imaging tests may include CT and positron emission tomography (PET) scans.

What scans are best for diagnosing astrocytomas?

MRI with contrast is the main scan for spotting and studying an astrocytoma because it shows brain and spinal cord tissue in much greater detail. CT is mainly used if MRI isn't possible or in emergencies. MRI with contrast helps doctors see both small, slow-growing and aggressive tumors clearly.

Does a pilocytic astrocytoma look different on an MRI?

On MRI, a pilocytic astrocytoma looks smoother and more organized. Higher grade tumors look rougher and more destructive in the surrounding tissue. A grade 1 pilocytic astrocytoma usually looks different from higher grade astrocytomas because it grows slowly. It also tends to stay well defined instead of blending into nearby brain tissue.

Pilocytic astrocytomas often look like cysts. They are round or oval masses with a fluid pocket. The tumor's solid part lights up clearly on the scan after the contrast is given. Pilocytic astrocytomas have clear borders and less swelling around them.

Higher grade astrocytomas, such as diffuse, anaplastic or glioblastoma types, often look more uneven and spread into nearby brain tissue. They usually have blurred edges, swelling around the tumor and patchy bright areas after contrast is given. These bright spots happen because parts of the tumor may have dead cells. Or they may have new and unusual looking blood vessels.

Special tests can provide detailed information about the tumor cells. Tests might look for changes in the genetic material of the tumor cells, called DNA. The information helps your healthcare team understand what to expect and decide on the best treatment for you.

Treatment

Astrocytoma treatment depends on the tumor's grade, size and location. Common treatments include surgery, radiation therapy and chemotherapy. In some cases, treatment may include targeted therapy or clinical trials.

• Surgery to remove the astrocytoma. A brain surgeon called a neurosurgeon works to remove as much of the astrocytoma as possible. The goal is to remove the whole tumor. If the tumor is in a spot that is hard to reach, it may be too risky to remove it all. Even so, taking out part of the astrocytoma can help ease your symptoms.

  For some people, surgery may be the only treatment needed. For others, more treatments may be recommended to kill any remaining tumor cells and lower the risk of the tumor coming back.

• Radiation therapy. Radiation therapy uses powerful energy beams to kill tumor cells. The energy can come from X-rays, protons and other sources. During radiation therapy, you lie on a table while a machine moves around you. The machine sends beams to exact points in your brain. The treatment only takes a few minutes.

  Radiation therapy may be recommended after surgery. It can be used if the cancer wasn't removed completely or if there's a high risk the cancer will return. Radiation also may be used with chemotherapy for cancers that grow quickly. For people who can't have surgery, radiation therapy and chemotherapy may be used as the main treatments.

• Chemotherapy. Chemotherapy uses strong medicines to kill tumor cells. Chemotherapy medicines can be taken in pill form or given through a vein. Sometimes, a circular wafer of chemotherapy medicine can be put in your brain during surgery. There, it slowly dissolves and releases the medicine.

  Chemotherapy is often used after surgery to kill any tumor cells that might remain. It also can be used with radiation therapy for tumors that grow quickly.

• Supportive care. Supportive care, sometimes called palliative care, helps manage pain and other symptoms of a serious illness. A team of specialists works with you, your family and your care team members to provide extra support. Supportive care can be given along with treatments such as surgery, chemotherapy or radiation. It often begins when treatment starts. You may not need to wait for complications to appear before receiving supportive care.

Surgery is usually the first step in treating astrocytoma. The goal is to remove as much tumor as is safely possible. What happens next depends on the tumor's grade, which is based on how the cells look and act under a microscope.

• Grade 1. Surgery is often the only treatment needed. These tumors grow slowly and are usually well defined, so they can often be removed completely. If the entire tumor is taken out, people often do not need further treatment.
• Grade 2. Treatment typically includes surgery, often followed by radiation therapy, chemotherapy or both. Even though these tumors grow slowly, they tend to spread into nearby brain tissue, which makes them harder to remove completely. Radiation therapy and chemotherapy help kill any remaining tumor cells and lowers the chance that the tumor will come back.
• Grades 3 and 4. Treatment often combines surgery, radiation therapy and the chemotherapy medicine temozolomide. Because these tumors grow and spread faster, healthcare professionals use a more aggressive approach. In some cases, targeted therapies such as IDH inhibitors or clinical trials also may be considered.

Your care team will create a treatment plan that fits your needs.

Astrocytoma treatment: Watchful waiting

Watchful waiting for low-grade astrocytoma, also called active surveillance, can be safe for some small, slow-growing tumors when the risks of surgery outweigh the benefits. But close monitoring is essential, and treatment should begin at the first sign of change.

Watchful waiting can be considered in select cases of low-grade astrocytoma, but it depends on several key factors:

• The tumor is small and does not cause symptoms. If the tumor was found by chance and does not affect brain function, your care team may monitor it closely with MRI scans instead of treating it right away.
• Surgery would cause high risk. If the tumor is in a deep or critical area of the brain where surgery could harm important functions, watchful waiting can sometimes be safer until there is clear growth or change.
• Diagnosis is uncertain. When the imaging suggests a low-grade tumor but a biopsy would be risky, watchful waiting can help track tumor growth over time.

Astrocytoma clinical trials and emerging treatments

Researchers are testing new astrocytoma treatments through clinical trials, including targeted therapy, immunotherapy and Tumor-Treating Fields (TTFields). Many of these treatments are still in clinical trials, where experts test new medicines and technologies to see how safe and effective they are. Clinical trials test new treatments such as vaccines, chimeric antigen receptor (CAR)-T cell therapy and viral therapies that target tumor cells directly.

A clinical trial may be an option for some people, especially if the tumor returns or stops responding to standard treatments. Some trials study targeted therapy, which uses medicines designed to act on certain proteins or genes in tumor cells. Other trials look at immunotherapy, which helps your body's defense system fight the tumor. Trials also are exploring better ways to combine surgery, radiation and chemotherapy.

Treatments being studied include:

• Temozolomide. Temozolomide is a chemotherapy medicine already used with radiation therapy to treat higher grade astrocytomas. Researchers are studying ways to make it work even better, such as changing how it's given or combining it with new treatments to improve results and lower side effects.
• IDH inhibitors. Some astrocytomas have changes in a gene called IDH. Medicines known as IDH inhibitors are being tested for people with this gene change. Studies suggest these treatments might help slow tumor growth, and more research is underway.
• Tumor-treating fields, also called TTFields. TTFields use low-intensity electrical fields to disrupt how cancer cells grow and divide. This treatment is already approved for glioblastoma, which is a high-grade astrocytoma. Studies show that TTFields can help people live longer when used with standard treatments such as radiation therapy. Researchers continue to study how best to combine TTFields with other therapies.

Taking part in a trial may give you access to these options before they are widely available. Because these treatments are still being studied, the risks and benefits may not yet be fully known. Your healthcare team can help you decide if a clinical trial is right for you.

How treatment differs for spinal cord or brainstem astrocytomas

Treatment for spinal cord astrocytoma and brainstem astrocytoma differs because surgery in these areas can affect vital nerves and functions.

Preparing for an appointment

See a healthcare professional if you have any symptoms that worry you. If your health professional thinks that you may have astrocytoma, you'll likely be referred to a specialist. This specialist might be a cancer doctor, called an oncologist. You also may see a surgeon who specializes in operating on the brain, called a neurosurgeon.

Because appointments may be quick, it helps to come prepared. Here's some information that may help you get ready.

What you can do

When you make the appointment, ask if there's anything you need to do ahead of time, such as not eating before a specific test. Make a list of:

• Your symptoms, even ones that don't seem related.
• Key personal information, including major stresses, recent life changes and family medical history.
• All medicines, vitamins or supplements you take, including the doses.
• Questions you'd like to ask.

Take a trusted family member or friend along, if possible, to help you remember the information you're given.

For astrocytoma, some basic questions to ask your healthcare professional include:

• Do I have cancer?
• If the tumor isn't cancerous, do I still need to have it removed?
• Do I need more tests?
• What are my treatment options?
• What are the potential risks or side effects for these treatment options?
• Will any of these treatments cure my cancer?
• Can I have a copy of my pathology report?
• How much time can I take to consider my treatment options?
• Are there brochures or other printed materials that I can take with me? What websites do recommend?
• What would happen if I decide not to have treatment?

Don't hesitate to ask any other questions you have.

What to expect from your doctor

Your healthcare professional is likely to ask you several questions, such as:

• When did your symptoms begin?
• Do your symptoms come and go, or are they constant?
• How severe are your symptoms?
• What, if anything, seems to improve your symptoms?
• What, if anything, appears to worsen your symptoms?

What is the survival rate for the different grades of astrocytoma?

• Grade 1, also called pilocytic, is usually cured with surgery. The five-year survival rate is around 96%.
• Grade 2, also called diffuse, astrocytomas have a median survival of about 7 to 8 years.
• Grade 3, also called anaplastic, astrocytomas have a median survival of about five years.
• Grade 4, also called glioblastoma, astrocytomas have a median survival of about 14 to 15 months.

How does IDH-mutant status change life expectancy?

• An IDH mutation is linked with longer survival and better response to therapy compared with IDH-wild-type tumors.
• For grade 2 disease, a change to the IDH1 gene is specifically linked with longer survival and has a better outlook than IDH wild type.

What is the prognosis for pilocytic astrocytoma in children?

Pilocytic astrocytoma (grade 1) in children is slow growing and often cured with surgery. The five-year survival rate is about 96%.

Anaplastic astrocytoma (grade 3): Factors linked to longer survival

Some people with anaplastic astrocytoma, also called grade 3, live much longer than the average five-year survival. In general, people with IDH-mutant tumors, who are younger, recover well from surgery, and receive both chemotherapy and radiation, are the most likely to have long-term survival.

Several factors can help improve outcomes:

• More complete tumor removal. When surgeons can safely remove most or all the tumor, people tend to live longer. The exact amount removed often makes a big difference.
• Combined treatment. Using surgery followed by both radiation and chemotherapy gives the best survival rates for high-grade tumors.
• Favorable tumor genetics. Tumors with certain gene changes, such as an IDH or MGMT gene change, tend to grow more slowly and respond better to treatment.
• Younger age and good overall health. Younger people and those with fewer neurological symptoms at diagnosis tend to do better.

Astrocytoma treatment is personalized. Surgery is usually first, followed by radiation or chemotherapy or both based on the tumor's grade and genes. Some people also may receive targeted therapy. Supportive care, also called palliative care, can start early to control symptoms and protect quality of life. New options, such as gene-targeted medicines and immunotherapy, are being tested in clinical trials and may expand choices over time.