Doctors may refer to an astrocytoma as a low-grade glioma or high-grade glioma. An astrocytoma is classified as low-grade or high-grade based on how it looks under a microscope.
Treatment for astrocytoma usually includes surgery to remove the tumor. Patients may also have chemotherapy or radiation therapy. Other treatments such as targeted therapy or immunotherapy may be used based on the type of tumor.
The survival rate for pediatric astrocytoma depends on the tumor’s type and location and whether it can be removed by surgery. Your child’s care team is the best source of information about your child’s case.
Symptoms of astrocytoma
Some tumors do not cause any symptoms until they become large. Symptoms may be gradual and hard to notice. Other times, symptoms may be severe and develop quickly.
Symptoms of astrocytoma depend on factors such as the child’s age, the tumor’s location and size, and how fast the tumor grows.
Astrocytoma symptoms in children may include:
Headache, often worse in the morning or improves after vomiting
Nausea and vomiting
Vision, hearing, and speech problems
Loss of balance or problems walking
Changes in personality or behavior
Fatigue or sleepiness
Unexplained weight gain or loss
Increase in head size (in infants)
As the tumor grows, it often blocks the normal flow of cerebrospinal fluid (CSF). This causes a buildup of fluid within the brain known ashydrocephalus. The fluid increases pressure in the brain. Hydrocephalus may cause some astrocytoma symptoms.
Risk factors for astrocytoma
For most children, there is no known cause of astrocytoma.
Astrocytoma tumors are classified by how they look under the microscope. Tumor grades are grades 1–4. The more abnormal the cells look, the higher the grade.
Grade 1 and 2 tumors are low-grade. The cells tend to grow slowly. The prognosis for low-grade astrocytoma is good, especially in children.
Grade 3 and 4 tumors are high-grade. They are aggressive and grow more quickly. The prognosis for high-grade tumors is much worse than for low-grade tumors. But this can depend on the treatments that are available.
Pilocytic astrocytoma (or juvenile pilocytic astrocytoma) is the most common pediatric brain tumor. It is a low-grade tumor. It rarely becomes a higher-grade tumor.
Pilocytic astrocytoma is a slow-growing tumor. It seems to grow in phases. In children, these tumors are often in the cerebellum and optic pathway. Surgery is the main treatment for pilocytic astrocytoma. Due to the risk of injuring nearby brain structures during surgery, not all tumors (such as optic pathway gliomas) can be completely removed.
Pilocytic astrocytoma has a 90% survival rate at 10 years in the United States. But infants tend to have a worse prognosis than older children.
Treatment of astrocytoma
Treatment 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 patient’s age. Doctors avoid radiation therapy in very young children. That is because the risk of severe side effects is higher.
Surgery to remove as much of the tumor as possible is the main treatment for astrocytoma. For patients with grade 1 tumors, surgery alone may be an effective treatment.
The goal is to completely remove the tumor (total gross resection). But this may not always be possible. This is due to the risk of damage to nearby brain structures.
Chemotherapy is often used with surgery. It may be the main treatment if surgery is not possible. Very young children may get chemotherapy to delay radiation therapy until they are older.
The chemotherapy treatment plan depends on factors such as spread of disease and molecular markers of the tumor.
Chemotherapy for low-grade astrocytoma may include:
Patients may also have other chemotherapy, especially in a clinical trial.
But chemotherapy alone does not usually cure low-grade astrocytoma. It may be a long-term or chronic disease if not removed by surgery.
Radiation therapy may be used based on the tumor type and location, and the child’s age. It is often used after surgery in high-grade astrocytoma to kill any cancer cells left behind.
Targeted therapies work by acting on, or targeting, certain features of tumor cells. These drugs change signals and processes that cancer cells use to grow, divide, and send messages to other cells. Stopping these activities helps kill cancer cells. Targeted therapies are mainly used to treat low-grade astrocytoma.
In most low-grade astrocytomas, there appears to be a change in the BRAF gene. The BRAF gene helps control a protein important for cell growth and function.
Depending on the type of mutation, certain drugs can be used to block signals that help tumor cells grow.
Targeted therapies under study for astrocytoma include:
BRAF inhibitors such as vemurafenib and dabrafenib. They may be used for tumors with a BRAF V600 gene mutation.
MEK inhibitors such as selumetinib or trametinib. They can be used in the case of BRAF fusion/duplication or low-grade astrocytoma in patients with NF1.
mTOR inhibitorseverolimus or sirolimus. They can be effective in low-grade astrocytoma, especially in patients with tuberous sclerosis complex.
Immunotherapy uses the body’s immune system to find and attack cancer cells. Immunotherapy drugs called immune checkpoint inhibitors are under study for astrocytoma. They help block signals from cancer cells that tell the body’s immune cells not to attack.
Steroid and anti-seizure medicines may 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.
The chance of cure depends on the type of tumor and its location. Some low-grade astrocytomas have a survival rate of 95% or higher in the United States. But certain high-grade astrocytomas have a survival rate of 10–30%. Clinical trials may be an option.
Factors that influence chance of cure include:
Type and grade of the tumor: Low-grade astrocytomas grow more slowly. They are less likely to come back. High-grade astrocytomas can be harder to treat and often come back.
Location of the tumor: Tumors in the cerebrum or cerebellum have a greater chance of cure. Tumors in the middle of the brain or brainstem have a lower chance because they are hard to remove with surgery.
If surgery can completely remove the tumor: Children who have no visible tumor after surgery have the best chance of cure.
Age at diagnosis: Children with low-grade astrocytoma who are older than age 3 at diagnosis tend to have a better outcome compared to younger children. In high-grade astrocytoma, patients diagnosed at a young age tend to do better.
Whether the cancer has spread: Cancer that has 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: Disease that has come back (recurrent) 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. This could include targeted therapy.
Support for patients with astrocytoma
Recovery and long-term effects of astrocytoma in children depend on the type of tumor and treatments received. Rehabilitation therapy may be needed. Patients should have regular follow-up care, lab tests, and imaging tests.
Pediatric low-grade astrocytoma as a long-term disease
Low-grade astrocytoma or glioma is often a chronic or long-term disease. Overall survival from low-grade glioma is high. But the tumor often comes back or gets worse over time. Patients may need more treatments. This means the patient is at risk for more complications from the tumor or its treatment.
Sometimes a tumor may show growth on a scan, but the care team recommends observation (watchful waiting) instead of treatment. Good communication and trust among the patient, family, and care team help aid decision making and disease management.
Regular checkups and screenings are important to watch for health problems that can develop years after therapy.