An astrocytoma is a tumour that arises from the star-shaped cells (astrocytes) that form the supportive tissue of the brain. WHO classifies astrocytomas into four grades depending on how fast they are growing and the likelihood that they will spread (infiltrate) to nearby brain tissue. Non-infiltrating astrocytomas usually grow more slowly than the infiltrating forms. Treatments include surgery, radiotherapy and chemotherapy. You may have a combination of these. Your doctor may prescribe steroids to reduce symptoms and drugs to prevent seizures (fits).