What is Astrocytoma Glioma?

Astrocytomas are tumours that arise from brain cells called astrocytes. Gliomas originate from glial cells, also called astrocytes. You will often hear the term Astrocytoma and Glioma used interchangeably. Astrocytomas account for majority of childhood brain tumours. In children, more than 80% of astrocytomas are low-grade and 20% high-grade.

Low-grade astrocytomas are usually well localised and grow slowly over a period of time. High-grade astrocytomas tend to grow rapidly, and infiltrate healthy brain tissue surrounding the tumour. These tumours therefore require more intensive treatment.

Signs & Symptoms

The signs and symptoms children initially present with, or continue to experience, is dependent upon the location of the tumour and age of the child. The most common area for these tumours to occur is within the cerebellum. This is the area above the back of the neck. Children with cerebellar tumours experience symptoms including headache and nausea and vomiting (occurring mostly in the morning), changes in coordination and an unsteady, clumsy walk. Two thirds of these tumours are cystic (have a fluid cyst associated with a solid tumour mass).

Less frequently these tumours arise in the cerebral hemispheres. These hemispheres (left and right) are located at the top part of the brain. Children may experience seizures and weakness in their arms and legs as a result of a tumour in this location.

Children who present with a tumour in the area of the optic nerve and hypothalamus often present with visual disturbances (decrease in vision and double vision) and hormone problems. Optic nerve gliomas are commonly low-grade tumours, and occur along the optic nerve, the optic chiasm and in the area of the hypothalamus. Tumours arising in the thalamic region (centre of the brain) can cause headaches and arm and leg weakness.

Tumour classifications and their Treatment

• Pilocytic Astrocytoma (low grade astrocytoma)
  These are slow growing tumours with fairly well defined borders. If the tumour is in an accessible location, the Neurosurgeon will aim at achieving a complete surgical removal. If this is achieved, no further treatment is required. Long term survival rates for a totally resected Pilocytic Astrocytoma are 90% at 25 years from diagnosis.
  Sometimes these tumours may infiltrate healthy brain tissue. This therefore makes it difficult for the entire tumour to be removed without causing harm to the surrounding good tissue. If only a partial resection of the tumour is achieved, further treatment may be necessary. This is aimed at partially shrinking or halting tumour growth and includes a course of chemotherapy and possibly radiation treatment in the long term.
• Anaplastic Astrocytoma (high grade astrocytoma)
  These tumours tend to be more locally aggressive when compared to Pilocytic Astrocytomas. Some Anaplastic Astrocytomas are more responsive to treatment than others. The goal of surgery is for a complete resection without causing any harm to the healthy brain tissue surrounding the tumour. Chemotherapy and radiotherapy are needed to treat this tumour type.
• Glioblastoma Multiforme (GBM)
  These are high-grade tumours, representing approximately 9% of brain tumours in children. They contain a mixture of cell types, hence the word multiforme. GBM's are treated with an aggressive surgical removal followed by intensive chemotherapy and radiation treatment to the area of the brain where the tumour originated.

Follow Up Care

After treatment has finished, children visit clinic on a regular basis, and undergo MRI scans and other investigations throughout their childhood to detect any possible recurrence. Importantly, all children attend the Neuro-Oncology Long-Term Effects clinic, where they are regularly reviewed a by a group of specialists involved in monitoring the specific long term growth and and development needs of these patients.