Different malignant soft tissue tumours (sarcoma) in the gastrointestinal tract are termed gastrointestinal stromal tumours (GIST). This type of cancer is rare. In contrast to more common cancers such as stomach cancer or colon cancer, gastrointestinal stromal tumours do not originate from the mucosa but rather from connective tissue in the stomach or colon wall.
Gastrointestinal stromal tumours have only been recognised as tumours in their own right for approx. 10 years. They occur in the tissue of the stomach wall or the intestinal wall, which makes them connective tissue tumours (sarcoma). This type of cancer is rare. There are approx. 120 new cases in Switzerland every year. Gastrointestinal stromal tumours occur most frequently in the stomach, sometimes in the small intestine and very rarely in the colon, in the duodenum or in the oesophagus. Men are affected slightly more often than women; however, the disease usually occurs between the age of 55 and 65.
Mutations can be determined on particular genes in the majority of gastrointestinal tumours. These mutations, which are not genetic in nature and only occur as life progresses, cause uncontrolled cell growth. Unfortunately no one knows why mutations occur and whether there are particular risk factors.
Gastrointestinal stromal tumours cause very few symptoms, so they are often diagnosed when they are already quite large. Signs of tumours in the gastrointestinal tract include nausea, a feeling of fullness, pain and haemorrhaging. A feeling of fullness and nausea are the main focus if the tumour is located in the stomach. If the tumour is located in the oesophagus, this may also make it difficult to swallow. Gastrointestinal tumours in the colon usually manifest themselves through constipation and blood in the stool.
It is not easy to diagnose a gastrointestinal tumour. Different examinations must be carried out until the diagnosis is certain. This includes computed tomography or MRI images as well as a gastroscopy with the removal of tissue samples. Special molecular biological analyses are required to detect the defective gene in the tumours.
The manifestations of the gastrointestinal tumours and the stages of illness upon discovering the disease are very different. The treatment depends on the type of tumour, where it is located and the stage of the disease. Localised tumours without metastisation are surgically removed. If such tumours can be removed completely, the chances of recovery are good. Additional chemotherapy is usually also carried out after the surgery to prevent recurrences. For several years, there have been newer medications on the market which can slow down the growth of tumours that have already metastasised.