What is Astrocytoma
Astrocytoma is a type of brain tumor. It is a malignant, cancerous tumor that arises from the small, star-shaped, brain cells called astrocytes. Astrocytes are one of several types of brain support cells, called glial cells. An astrocytoma is a subtype of the group of brain tumors called gliomas.
Astrocytoma is the most common form of glioma. It can appear anywhere in the brain, although it is most often found in:
- The brain (adults): the largest part of the brain
- The cerebellum: a smaller part in the posterior region of the brain
- Brain stem: connects to the spinal cord
- Optic nerves (children): nerves that go from the brain to the eyes
When an astrocytoma is diagnosed, the most important factors are:
Tumor level (level of aggressiveness according to microscopic observation)
- Degree of neurological side effects produced by the tumor
- Patient’s age
These factors determine the symptoms, prognosis and treatment.
The exact cause is unknown. Some possible causes of brain tumors include:
- Certain occupations
- Environmental factors
Astrocytoma Risk factors
Although the exact risk factors of astrocytomas have not been identified, some studies suggest that the following factors increase your likelihood of having this tumor:
Genetic disorders (such as neurofibromatosis and tuberous sclerosis)
Occupational exposure to:
- Oil refining
- Rubber Manufacturing
The first symptoms of any brain tumor may appear as the tumor grows. Growth can increase the pressure on the brain. Symptoms may include:
- Visual changes
- Personality changes
- Problems of memory, concentration and thinking
- Problems with walking
Symptoms vary depending on the location of the tumor. For example:
- Frontal lobe: gradual changes in mood and personality, paralysis of one side of the body
- Temporal lobe: problems of coordination, speech and memory
- Parietal lobe: problems with sensations, writing or fine motor skills
- Cerebellum: coordination and balance problems
- Occipital lobe: problems with vision and visual hallucinations
The doctor will ask about your symptoms and medical history. You will have a physical exam. Tests may include:
- Magnetic resonance imaging: a test that uses magnetic waves to define the anatomy of the brain and is the most sensitive and clear way to define a brain tumor
- Computed tomography: x-ray device that takes circular images of the brain with x-rays
- Angiogram – x-rays taken after a contrast dye is injected into the arteries to allow the doctor to detect abnormalities in the arteries that go to the brain
- Biopsy or resection: removal of a sample of brain tissue to detect the presence of cancer cells
A specialist will determine the grade of the tumor. Astrocytomas are classified from I to IV. These grades indicate the prognosis and growth rate of the tumor.
- Astrocytoma Grades I and II : Astrocytomas grow slowly and remain in one region of the brain. They are seen more frequently in younger patients. Astrocytomas of grade II can expand.
- Astrocytoma Grades III and IV: These tumors grow rapidly and can spread throughout the entire brain and spine. An aggressive treatment is needed. This is the most frequent type in adults. Grade III tumors are called anaplastic astrocytomas.
- Grade IV tumors are called glioblastoma multiforme or GBM.
The treatment is based on the location, size and degree of the tumor. The treatment may include:
The surgery involves removing as much of the tumor as possible. If the tumor is high grade, radiation or chemotherapy is usually applied after surgery to help keep it from expanding.
Radiation therapy involves the use of radiation to kill cancer cells or reduce the tumor. Types of radiation:
- External radiotherapy: radiation is applied to the tumor from an external source to the body
- Internal radiation therapy (also called brachytherapy): radioactive materials are placed inside the body near cancer cells
Chemotherapy is the use of drugs to kill cancer cells. It can be administered in many forms, such as pills, injections and through a catheter (IV or port of access). The drugs enter the bloodstream, travel through the body and kill, mainly, the cancer cells. They also kill some healthy cells.
How to Prevent Astrocytoma
There are no prevention guidelines, since the precise cause is unknown. It has been suggested that electromagnetic waves emitted by high-voltage cables or even cell phones can increase the risk of brain tumors. Currently, this theory has not been scientifically proven.