Astrocytoma in Children and Teens

What is astrocytoma?

Astrocytomas are tumors of the brain and spinal cord that grow from cells called astrocytes. Astrocytes are a type of glial cell which make up the brain's supportive tissue. Astrocytomas are the most common type of childhood brain tumor. They account for about half of all central nervous system (CNS) tumors in children.

Places for astrocytomas to develop include the:

• Cerebellum
• Cerebrum
• Brainstem
• Hypothalamus
• Visual Pathway - also see Optic Pathway Tumor
• Spinal cord

Astrocytomas are classified as low-grade or high-grade based on how they look under the microscope. Treatment for astrocytoma usually includes surgery to remove the tumor. Chemotherapy or radiation therapy are often used along with surgery to kill any remaining cancer cells. Other treatments may be used based on the type of tumor.

The survival rate for pediatric astrocytoma depends on the type of tumor, where it is located, if it can be removed with surgery, and if there are other effective treatments for the tumor type.

Symptoms of astrocytoma

Signs and symptoms of childhood astrocytoma can vary. Some tumors do not cause any symptoms until they grow to be very large. In some cases, symptoms may be gradual and hard to notice, especially in low-grade astrocytoma. Other times, symptoms may be severe and develop quickly, especially in the case of high-grade or fast-growing tumors.

Symptoms of astrocytoma depend on factors such as the child’s age, where the tumor is located, the size of the tumor, and how fast the tumor grows.

Astrocytoma symptoms in children may include:

• Headache, which is often worse in the morning or improves after vomiting
• Nausea and vomiting
• Vision problems
• Loss of balance or problems walking
• Weakness, numbness, tingling, or changes in sensation on one side of the body
• Changes in personality or behavior
• Seizures
• Changes in speech
• Changes in hearing
• Fatigue or sleepiness
• Changes in school or work performance
• Unexplained changes in weight (gain or loss)
• Symptoms due to endocrine problems such as unexplained thirst or early puberty
• Increased head size in infants
• Increased fullness of the fontanel ("soft spot" at the top of the skull)

As the tumor grows, it often blocks the normal flow of cerebrospinal fluid. This causes a buildup of fluid within the brain known as hydrocephalus. The fluid increases pressure in the brain (intracranial pressure). Some symptoms of astrocytoma may be due to hydrocephalus.

Diagnosis of astrocytoma

Tests to diagnose astrocytoma include:

• A physical exam and medical history helps doctors learn about symptoms, general health, past illness, and risk factors.
  • Risk Factors: For most children, there is no known cause of astrocytoma. However, there are certain factors that may increase risk. These inherited conditions include neurofibromatosis type 1 (NF1) and tuberous sclerosis. Children with Li-Fraumeni syndrome are also more likely to have astrocytomas. Past radiation therapy to the brain also increases risk.
• A neurological exam measures different aspects of brain function including memory, vision, hearing, muscle strength, balance, coordination, and reflexes.
• A comprehensive eye exam evaluates different aspects of eye health and vision. An eye exam can also detect increased pressure around the brain.
• Imaging tests are used to help identify the tumor, see how big the tumor is, and find out what brain areas may be affected.
  • Magnetic resonance imaging (MRI) is the main imaging technique that is usually used to evaluate astrocytoma. The images made by MRI can give more information about the type of tumor and the potential spread of disease. An MRI is also done after surgery to see if any tumor remains.
  • Computed tomography (CT scan) uses X-rays to create cross-sectional images of the organs and tissues inside the body. The machine takes many pictures to make a very detailed image. This can allow very small tumors to be seen.
• A biopsy is usually used to diagnose astrocytoma. In a biopsy, a small sample of the tumor is removed during surgery. A pathologist looks at the tissue sample under a microscope to identify the specific type and grade of astrocytoma.

Grading and staging of astrocytoma

Astrocytoma tumors are classified by how they look under the microscope. A tumor is graded from grade I to grade IV. The more abnormal cells look, the higher the grade.

Grade I and II tumors are considered low grade. The cells look less aggressive and tend to grow slowly. The prognosis for low-grade astrocytoma is good in general, especially in children.

Grade III and IV tumors are considered high grade. They are aggressive and grow more quickly. The prognosis for high-grade tumors is much worse than for low-grade tumors. However, this can depend on what treatments are available for the specific type of tumor. 

Most astrocytomas in children are low grade. In adults, astrocytomas tend to be high grade.

Classification of astrocytoma by tumor grade

What is pilocytic astrocytoma?

Pilocytic astrocytoma (or Juvenile Pilocytic Astrocytoma) is the most common pediatric brain tumor. It is a low-grade tumor. It rarely progresses to a higher grade. Pilocytic astrocytoma has a 90% survival rate at 10 years. However, infants tend to have a worse prognosis than older children.

Pilocytic astrocytoma is a slow growing tumor and seems to grow in phases. In children, these tumors often occur in the cerebellum and optic pathway. Surgery is the main treatment for pilocytic astrocytoma. However, not all tumors (such as Optic Pathway Gliomas) can be completely removed with surgery due to risk to nearby brain structures.

Prognosis for astrocytoma

The chance of cure can vary greatly depending on the specific type of tumor and its location. Some low-grade astrocytomas have a survival rate of 95% or higher with successful surgery. However, certain high-grade astrocytomas have a survival rate of 10-30%.

Factors that influence chance of cure include:

• Type and grade of the tumor. Low-grade astrocytomas grow more slowly and are less likely to recur. High-grade astrocytomas can be harder to treat and often recur.
• Location of the tumor. Tumors located in the cerebrum or cerebellum have a greater chance of cure compared to tumors in the middle of the brain or brainstem. This is largely due to how hard it is to remove the tumor with surgery.
• If surgery can completely remove the tumor. One of the most important factors for prognosis is whether surgery can completely remove the tumor. Children who have a gross total resection with no visible tumor after surgery have the best chance of cure.
• Age at diagnosis. The effect of age on prognosis depends on the specific tumor type. Children with low-grade astrocytoma who are older than 3 years of age at diagnosis tend to have a better outcome compared to younger children. In high-grade astrocytoma, patients who are diagnosed at a young age tend to do better.
• Whether the cancer has spread. Cancer that has metastasized or spread to other parts of the brain or spine is harder to treat.
• Whether the child has NF1. Patients with low-grade astrocytoma who have neurofibromatosis type 1 (NF1) tend to do better than patients who do not have NF1.
• If the cancer is new or if it has come back. Recurrent disease is harder to treat.
• Molecular features of the tumor. Certain changes in genes and cell features of the tumor can make the disease easier to treat or allow for specific new emerging treatments (called targeted therapy).

Treatment of astrocytoma

Treatment of astrocytoma depends on the type of tumor, its location, and whether it has spread or has come back. Aggressive tumors need more intensive treatment. Doctors also consider the age of the patient. Doctors try to avoid radiation therapy in very young children because the risk of severe side effects is higher.

Steroid and anti-seizure medications may be needed to help manage symptoms. Some children with hydrocephalus due to astrocytoma may have a shunt placed in the brain to prevent cerebrospinal fluid from building up. A shunt is a small tube that drains fluid from the brain.

Care for patients with astrocytoma should include appropriate referrals to support services such as endocrinology, ophthalmology, rehabilitation therapy, school services, and psychology.

Life after pediatric astrocytoma

Recovery and long-term effects of astrocytoma in children depend on the type of tumor and treatments received. Ongoing follow-up care, laboratory tests, and routine imaging are needed to monitor patients for recurrence or progression of disease. The care team will set a schedule based on type of tumor, response to treatment, and individual patient needs.

An interdisciplinary team can help meet individual patient needs to promote long-term health and quality of life. Regular checkups and screenings throughout survivorship are important to watch for health problems that can develop years after therapy.

More: Life After Brain Tumors