Gastrointestinal Stromal Tumor - GIST: Stages

This section has been reviewed and approved by the Cancer.Net Editorial Board, 12/2014

ON THIS PAGE: You will learn about how doctors describe a tumor’s growth or spread. This is called the stage. To see other pages, use the menu on the side of your screen.

Staging is a way of describing where the tumor is located, 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 the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis, which is the chance of recovery. There are different stage descriptions for different types of cancers.

For other types of GI tumors, the most common staging tool used is called the TNM system. TNM is an abbreviation for tumor (T), node (N), and metastasis (M). However, the use of the TNM system for GISTs is not required. Instead, doctors look at different factors to determine a patient’s prognosis and the specific risk of how aggressive an individual tumor will be. Specifically, doctors want to figure out how quickly the GIST may grow and the chance the tumor will come back, or recur, after surgery.

Doctors commonly use the factors listed below to determine how aggressive a GIST will be:

  • The size of the tumor
  • The mitotic count, which describes the actual number of dividing cells
  • The location where the tumor started

Information about the tumor’s aggressiveness will help the doctor recommend a treatment plan.  The next section helps explain the treatment options for this type of tumor. Use the menu on the side of your screen to select Treatment Options, or you can select another section, to continue reading this guide.