The grade of the tumor is used in place of a staging system to plan cancer treatment.

Staging is the process used to find out how much cancer there is and if cancer has spread. It is important to know the stage in order to plan treatment.

There is no standard staging system for childhood cerebellar astrocytoma. Instead, the grade of the tumor is used to plan treatment. The grade of the tumor describes how abnormal the cancer cells look under a microscope and how quickly the tumor is likely to grow and spread.

The following grades are used:

• Grade I pilocytic tumor is a tumor that is very slow-growing and rarely spreads. These tumors form inside cysts.
• Grade II diffuse or fibrillary tumor is a tumor that usually spreads slowly within the cerebellum.

Cerebellar astrocytomas usually do not spread from the cerebellum to other parts of the brain or body.

The information from tests and procedures done to detect (find) childhood cerebellar astrocytoma is used to plan cancer treatment.

Some of the tests used to detect childhood cerebellar astrocytoma are repeated after the tumor is removed. (See the General Information section.) This is to find out how much tumor remains after surgery and plan further treatment.