What is a Gastrointestinal Stromal Tumor?

A gastrointestinal stromal tumor is a rare type of malignancy. When this type of cancer develops, it affects the patient’s digestive system, or it may develop on structures that are adjacent to the digestive tract. A gastrointestinal tumor is referred to as a sarcoma, which means it doesn’t usually develop within an organ. Instead, it usually begins in connective and supportive tissues of the body. For example, a sarcoma may begin to grow from cancerous cells in a patient's cartilage, tendons, or bones; it may even develop in a person’s muscles, fat, or blood vessels.

Gastrointestinal stromal tumors differ from may other types of cancer in terms of the direction in which they grow. These cancers typically develop in the wall of a person’s gastrointestinal tract and attach to the outside of the nearby organ. As such, these tumors usually grow outward instead of inward. Once in a while, however, this type of tumor does grow inward. In such a case, it may go through that the gastrointestinal tract walls and then start to grow, at least in part, inside the digestive tract.

When a tumor is called a primary gastrointestinal stromal tumor, this basically means it developed at the original location of the cancer. A secondary tumor, on the other hand, is one that has spread from its initial location. Typically, a primary gastrointestinal tumor affects the stomach, but this type of tumor may develop in other areas as well, such as the small intestine. Less frequently, a primary gastrointestinal tumor will affect a person’s esophagus or rectum. It may also develop in other parts of the body, but such occurrences are extremely rare.

Most cases involving gastrointestinal stromal tumors develop in individuals who are over 50 years old. Even among people who are older than 50, however, the condition is rare. Scientists have been unable to pinpoint any environmental factors that lead to its development. It appears that it may be caused by a gene mutation and does not usually run in families.

Most people who have gastrointestinal stromal tumors do not develop symptoms at first. Symptoms may develop, however, if the tumor grows large enough to press on organs or structures, or crowd the abdominal cavity. In such a case, gastrointestinal stromal tumor symptoms may include fullness in the area, abdominal pain, unexplained weight loss, and digestive difficulties. In some cases, very large growths may even be visible through the affected person’s abdomen.

A person with a gastrointestinal stromal tumor may be treated with surgery to remove the tumor. Sometimes chemotherapy or radiation therapy may be used, but they are often less effective against this type of tumor. Doctors may also use biological therapy to stop the tumor from growing.