Astrocytomas are the most common brain tumors in children, accounting for up to 40%. These tumors are usually diagnosed between ages 5 years and 9 years.
Pressure within the skull increases, causing headaches (often when children first awaken), vomiting, and listlessness. Children may lose their coordination and have difficulty walking. Vision may be blurred or lost, and the eyes may bulge or involuntarily jerk in one direction, then drift back (nystagmus).
Astrocytomas in the spinal cord may cause back pain, difficulty walking, and muscle weakness.
Then doctors must take a sample of tissue from the tumor and examine it under a microscope (biopsy) because treatment is based on how abnormal the tumor cells look (the tumor’s grade). These tumors are typically classified as low grade (for example, juvenile pilocytic astrocytoma) or high grade (for example, glioblastoma). Grades I and II tumors are low grade, and grades III and IV tumors are high grade.
(See also Cancer Treatment Principles.)
Most low-grade astrocytomas are surgically removed. If the astrocytoma is completely removed, children may not need any other treatment.
Sometimes, separating the tumor from normal brain tissue is too difficult, or the tumor is inaccessible. In such cases, radiation therapy is used instead. Radiation therapy is used in children who are over age 10 years who have a tumor that cannot be removed surgically, that is likely to impair intellectual functioning, or that progresses or returns after surgery. If children are younger than 10 years, chemotherapy may be used instead of radiation therapy because radiation therapy can interfere with growth and brain development in young children. Most low-grade astrocytomas can be cured.
High-grade astrocytomas are treated with a combination of surgery (if possible), radiation therapy, and chemotherapy (see Combination Cancer Therapy). The outlook is worse for children with a high-grade tumor, in whom the overall survival is only 20 to 30% 3 years after treatment.