Astrocytomas

Astrocytomas are tumors that begin in supportive brain cells called astrocytes. They make up about 2 in 10 brain tumors. Many astrocytomas spread widely through the brain and blend with healthy tissue, which can make them hard to remove with surgery.

Sometimes they spread along the cerebrospinal fluid (CSF) pathways. It's very rare for them to spread outside the brain or spinal cord.

Types and Stages

Like other brain tumors, astrocytomas are grouped by grade. The grade reflects how quickly the tumor is likely to grow and spread.

Low-grade (grade I or II) astrocytomas tend to grow slowly. They include:

• Non-infiltrating (grade I). These usually don't grow into nearby tissue and often have a good outlook. Examples include pilocytic astrocytomas and subependymal giant cell astrocytomas (SEGAs), which are more common in children.
   
• Grade II. These include diffuse astrocytomas and pleomorphic xanthoastrocytomas (PXAs). They grow slowly but can reach into nearby areas and may become more aggressive over time.

High-grade (grade III or IV) astrocytomas grow quickly and spread into surrounding brain tissue. They include:

• Anaplastic (grade III). These grow faster and spread more easily than low-grade tumors.
   
• Glioblastomas (GBM), or grade IV. The fastest growing, these make up more than half of all gliomas and are the most common malignant brain tumors in adults.

Signs and Symptoms

Symptoms depend on where the tumor starts, since astrocytomas can form in the brain or the spinal cord.

In the brain, symptoms may include:

• Seizures, which may cause loss of consciousness or behavior changes, such as staring off
• Headaches
• Nausea and vomiting
• Personality changes
• Trouble speaking
• Feeling very tired or weak

In the spinal cord, symptoms may include:

• Pain in the affected area
• Pain that gets worse at night
• Weakness in the arms or legs that worsens over time
• Trouble walking

Diagnosis

Doctors use several tests to diagnose astrocytoma:

• Neurological exam. Your care team asks about your symptoms and checks vision, hearing, balance, coordination, strength, and reflexes. Problems can point to the affected part of the brain.
   
• MRI is used most often. It may include specialized scans like functional MRI, perfusion MRI, and magnetic resonance spectroscopy. CT and PET scans may also be used.
   
• A tissue sample is removed, often during surgery, or with a needle if the tumor is hard to reach. A lab then identifies the cell type and how quickly it grows.

Treatment

Treatment options for astrocytoma include:

• Surgery. A neurosurgeon removes as much of the tumor as safely possible. If the tumor is in a hard-to-reach spot, removing all of it may be too risky, but taking out part of it can ease symptoms.
   
• Radiation therapy. Often used after surgery if the tumor wasn't fully removed or is likely to return. It may be paired with chemotherapy for fast-growing tumors, or used as a main treatment when surgery isn't possible.
   
• Chemotherapy. Strong medicines, taken as a pill or given through a vein, help kill tumor cells. A dissolving wafer of medicine may also be placed in the brain after surgery. Chemotherapy is often used after surgery and alongside radiation for fast-growing tumors.

Causes and Risk Factors

Risk factors for astrocytoma include:

• Age. It can happen at any age but is most common in adults between 30 and 55.
   
• Previous radiation, especially near the head or neck, can raise your risk.
   
• Conditions that run in families, such as neurofibromatosis type 1, Lynch syndrome, and Li-Fraumeni syndrome, can increase risk.

Screening

There is no routine screening for astrocytoma. Diagnosis depends on noticing symptoms and seeking prompt medical care.