The overall five-year survival rate for people diagnosed with a malignant gastrointestinal stromal tumor, based on data obtained between 2003 and 2009, is approximately 76 percent, according to the American Cancer Society. This data is the best available for determining a survival rate for this type of tumor.
A five-year survival rate is the percentage of people with a disease who survive at least five years following diagnosis, states the American Cancer Society. This rate is what doctors use to discuss a prognosis, but many people survive longer than five years. Per the 2003 to 2009 data, if the GIST has not spread further than one organ at the time of diagnosis, the five-year survival rate is 91 percent. If it has spread to distant parts of the body, the five-year survival rate drops to 48 percent.