This is the abnormal cells that develop in the tissues of the gastrointestinal tract which consists of the stomach, small intestine and the large intestine. The gastrointestinal stromal tumors can either be cancerous or non-cancerous and can develop in any part of the gastrointestinal tract although it is usually identified in the stomach and the small intestine.
Causes
It is estimated that around 80% of the cases develop as the result of the genetic mutation in the gene KIT and 10% occurs from the mutation in the PDGFRA gene. A small number of other genetic mutations are also identified to cause this condition. Both these genes are essential for the production of the receptor proteins that stimulate signaling pathways within the cells which control several cellular processes such as cell’s growth and division. The genetic mutation affects the signaling pathways that are continuously turned on which results in the uncontrolled cell growth. Most of the genetic mutations are not inherited. However, the familiar gastrointestinal stromal tumors are inherited in an autosomal dominant pattern meaning one copy of the defective gene is sufficient to cause this condition.
Symptoms
This occurs mostly among the adults between the age of 40 and 70 although it can also rarely affect the children. Some of the symptoms that are associated with gastrointestinal stromal tumors include feeling full after eating a small quantity of food, fatigue, blood in the stool or the vomit, abdominal pain and trouble with swallowing. The sporadic gastrointestinal stromal tumors can develop in individuals with no family history of this condition which is typically a single tumor. The familial gastrointestinal stromal tumors develop among those with the history of its presence in the family and often have multiple tumors. In addition, they may also exhibit a condition known as urticarial pigmentosa which is the presence of raised brownish patches on the skin that itch when touched.
Diagnosis
The diagnosis is based on the physical examination that seeks to identify signs such as lumps, the individual’s family history and their health. Additional diagnosis includes a CT scan, MRI imaging and endoscopic ultrasound. A biopsy of the affected tissue may also be removed during the endoscopy procedure which will be observed under the microscope for cancer cells. Some of the tests that are used to study the cancer cells include immunohistochemistry that makes the use of various antibodies in samples of tissues that detects certain antigens and mitotic rate that measures the growth rate of the cancer cells.
Treatment
The different types of treatment options for gastrointestinal stromal tumors include surgery to remove the tumor and some of the tissues around it when it has not spread, targeted therapy that identifies and destroys the specific cancer cells or to watch and wait until symptoms develop.
References
https://www.cancer.gov/types/soft-tissue-sarcoma/patient/gist-treatment-pdq#section/_52
https://ghr.nlm.nih.gov/condition/gastrointestinal-stromal-tumor#genes
https://www.cancer.org/cancer/gastrointestinal-stromal-tumor/about/what-is-gist.html
