Medulloblastoma - Childhood: Stages

Aprobado por la Junta Editorial de Cancer.Net, 08/2022

ON THIS PAGE: You will learn about how doctors describe this brain tumor’s growth or spread. This is called the stage. Use the menu to see other pages.

What is cancer staging?

Staging is a way of describing the size of a tumor, where it is located, if it is cancerous, if or where it has spread, and whether it is affecting other parts of the body.

Doctors use diagnostic tests to find out the tumor’s stage, so staging may not be complete until all of the tests are finished. Knowing the stage helps the doctor recommend the best kind of treatment and can help predict a patient’s prognosis, which is the chance of recovery. There are different stage descriptions for different types of tumors.

Medulloblastoma in children is classified as either standard (average) risk or high risk, depending on the following factors:

  • The child’s age

  • How much of the tumor remains after surgery

  • Whether the tumor has spread

Standard-risk tumor

The tumor is in the very back part of the brain and has not spread to other areas of the brain and spinal cord. Additionally, it is almost completely removed during surgery, meaning that less than 1.5 cubic centimeters (cm) of the tumor remains after surgery. However, the surgeon will usually prefer to remove all of the tumor if it can be completely removed without increasing the risk of severe side effects. Standard-risk tumors do not have molecular features that are linked with a worse chance of recovery.

High-risk tumor

Medulloblastoma has either spread to other parts of the brain or the spine, or it has not spread but more than 1.5 cubic cm of tumor remains after surgery. Some tumors that first appear to be standard-risk tumors will be found to have high-risk molecular features after testing is finished. In that case, the classification will change, and it will be treated as a high-risk tumor with the current standard treatment plans (see the Types of Treatment section).

Recurrent tumor

A recurrent tumor is a tumor that has come back after treatment. Medulloblastoma may recur in the brain, spine, spinal fluid, or, very rarely, elsewhere in the body. If the tumor does return, there will be another round of tests to learn about the extent of the recurrence. These tests and scans are often similar to those done at the time of the original diagnosis.

Information about the tumor’s risk classification will help the doctor recommend a specific treatment plan. The next section in this guide is Types of Treatment. Use the menu to choose a different section to read in this guide.