Gastrointestinal Stromal Tumours (GISTs)
Gastrointestinal Stromal tumours are relatively rare tumours that are found in the gastrointestinal tract. Unlike most types of gastrointestinal cancers, they occur in the connective tissue of the gastrointestinal area, and are known as “sarcomas”. Sarcomas are a rare type of cancer, but of all types of sarcoma, gastrointestinal stromal cancers are the most common, occurring in somewhere between 10-20 people per million. They tend not to have a genetic precedent, and most often occur sporadically throughout the population.
Most gastrointestinal stromal cancers begin in the wall of the gastronintestinal tract in cells known as ICCs, or “interstitial cells of Cajal”, while many others—more than half—actually start in the stomach area. Not all gastrointestinal stromal tumours are malignant and cancerous, however, with many classified as relatively benign in nature. However, even benign tumours have some malignant potential. Gastrointestinal stromal cancerous tumours account for roughly 1-3 per cent of all gastrointestinal cancers.
The symptoms of gastrointestinal stromal cancers often include difficulty swallowing, bleeding from the gastrointestinal area, ie in the stool, as well as metastases of the cancer to other areas of the body. The gastrointestinal stromal cancers tend to grow outwards, meaning that blockages of the intestine are relatively rare as a system. Long-term discomfort or pain in the intestinal area is often reported, but this is often reported in cases where the gastrointestinal stromal cancer has typically been growing for some time. Gastrointestinal stromal cancers tend to grow fairly slowly when small, but when large may move to the liver and peritoneal cavity. It is rare for them to occur within other organs of the abdomen.
Gastrointestinal stromal cancers are usually diagnosed by means of a biopsy using an endoscope. Blood tests and CT scans are also frequently used as diagnostic methods. Surgery to remove the gastrointestinal stromal tumour is the most common approach to treating this type of cancer, but if the cancer has metastasised, then some types of inhibitor drugs such as imatinib can be of some assistance. Chemotherapy is usually not used against gastrointestinal stromal cancers, as they tend to be extremely resistant to this kind of treatment. Some types of alternative treatments designed to help improve the patient’s immune system and boost overall health have been trialled as a way of helping to combat the spread and growth of gastrointestinal stromal cancers, and may have some efficacy in fighting a return of the cancer.