(GIST; Tumor, Gastrointestinal Stromal; Gastrointestinal Stromal Sarcoma; Gastric Myosarcoma; Gastric Myoblastoma; Gastrointestinal Leiomyosarcoma; Gastrointestinal Smooth Muscle Tumor)
Definition
Definition
Gastrointestinal stromal tumors (GISTs) are a type of tumor that occur in the digestive system. The digestive system includes the esophagus, liver, stomach, gall bladder, large and small intestines, rectum, and anus. The digestive system processes food to fuel the body and gets rid of waste. About half of GISTs occur in the stomach, but they can occur anywhere in the digestive system.
GISTs are rare. All GISTs are now considered potentially cancerous.
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Causes
Causes
The cause of GISTs is not well understood.
Many people with GIST have a defect in a gene called c-kit. Usually, this gene is not active. However, in people with GIST, the c-kit gene often has a defect and is active, which enables the cells to grow and divide uncontrollably. This may explain why a GIST forms.
Theories about GISTs say that they begin in special cells of the digestive system. These cells are called interstitial cells of Cajal (ICCs). They send signals that tell the digestive system to contract, which moves food and liquid through the digestive system.
Risk Factors
Risk Factors
GIST is most common in people over age 50. It is rare in children. Risk factors for GIST are mostly unknown. Other possible risk factors include:
- Neurofibromatosis—a genetic disorder of the nervous system
- Family history of GIST—rare
Symptoms
Symptoms
GISTs may not cause any symptoms until they grow to a certain size. Symptoms may include:
- Tiredness and weakness
- Fever or sweating at night
- Weight loss
- Feeling full after eating a small amount of food
- Abdominal pain
- Painless lump in the abdomen
- Nausea and/or vomiting
- Blood in stool or vomit
- Problems swallowing
Diagnosis
Diagnosis
Your doctor will ask about your symptoms and medical history. A physical exam will also be done.
Imaging tests can assess the location and size of the tumor. These may include:
Tissues can be tested with a fine-needle biopsy.
Treatment
Treatment
Talk with your doctor about the best treatment plan for you. Treatment options include:
Surgery
Surgery is used to treat a GIST that has not spread. Surgery to treat GIST should be done by an experienced cancer surgeon. GISTs are delicate tumors. There may be an increased risk of cancer spreading if the sac surrounding the GIST is opened during surgery.
You may be given medications to shrink the tumor before surgery. For small tumors, laparoscopic surgery may be used.
Even if the tumor is large or growing into other organs, your doctor may use surgery to remove some or the entire tumor. This reduces the chance that the tumor will grow large enough to block the digestive system.
Medication
You may be given a medication called a tyrosine kinase inhibitor. It may make the tumor shrink or stop growing.
Prevention
Prevention
There are no current guidelines to prevent GISTs.
RESOURCES:
American Gastroenterological Association http://www.gastro.org
CANADIAN RESOURCES:
Canadian Cancer Society http://www.cancer.ca
References:
Huang HY, Li CF, Huang WW, et al. A modification of NIH consensus criteria to better distinguish the highly lethal subset of primary localized gastrointestinal stromal tumors: A subdivision of the original high-risk group on the basis of outcome. Surgery. 2007;141(6):748
Demetri GD, von Mehren M, Blanke CD, et al. Efficacy and safety of imatinib mesylate in advanced gastrointestinal stromal tumors. N Engl J Med. 2002;347(7):472-480.
Duffaud F, Blay J. Gastrointestinal stromal tumors: Biology and treatment. Oncology. 2003;65(3):187-197.
Gastrointestinal stromal tumor. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated December 12, 2012. Accessed June 20, 2014.
Gastrointestinal stromal tumor. Ped Surg Update. 2005;24(6):3.
What are gastrointestinal stromal tumor (GIST). American Cancer Society website. Available at:
http://www.cancer.org/cancer/gastrointestinalstromaltumorgist/detailedguide/gastrointestinal-stromal-tumor-what-is-gist
Updated February 26, 2013. Accessed August 14, 2013.
Gastrointestinal stromal tumors (GISTs). Macmillan Cancer Support website. Available at:
http://www.macmillan.org.uk/Cancerinformation/Cancertypes/Softtissuesarcomas/Typesofsofttissuesarcomas/GIST.aspx
Updated January 1, 2013. Accessed August 14, 2013.
Rubin BP, Heinrich MC, Corless CL. Gastrointestinal stromal tumour. Lancet. 2007;369(9574):1731-1741.
Shinomura Y, Kinoshita K, Tsutsui S, Hirota S. Pathophysiology, diagnosis, and treatment of gastrointestinal stromal tumors. J Gastroenterol. 2005;40(8):775-780.
Last Updated: 5/11/2013