Gastrointestinal stromal tumors are tumors that occur in the gastrointestinal tract, according to the American Cancer Society. GISTs are less common than other types of gastrointestinal tract cancers, and they can be either benign or cancerous.
Treatment for a GIST depends on factors such as tumor size and location, whether or not it has spread and how fast it is growing, says Cleveland Clinic. A small tumor that has not spread is low risk and is likely to be cured with surgery. A large tumor or a tumor that has spread is intermediate or high risk, and it is likely to be treated with a medication called imatinib, which is taken orally once or twice daily to help shrink the tumor or halt its growth.