About gastrointestinal stromal tumors

What is gastrointestinal stromal tumors?

Gastrointestinal stromal tumors (GIST) belong to a group of cancers known as soft tissue sarcomas. The number of new cases in the United States annually has been estimated to be 5,000-6,000. Tumors usually arise from the intestinal tract with the most common site being the stomach, followed by the small intestine, and the colon/rectum with rare cases arising in the esophagus. There are also tumors that appear to arise in the membranous tissue lining the wall of the stomach (peritoneum) or in a fold of such membranous tissue (the omentum). There are also case reports of tumors arising in the appendix and/or pancreas. These tumors most commonly present with abdominal pain, bleeding or signs of intestinal obstruction. They spread most commonly to sites within the abdominal cavity and to the liver, although there are rare cases of spread to the lungs and bone. GIST results from a change in one of two genes, KIT or PDGFR, which leads to continued growth and division of tumor cells. There are a few reported cases of families in which a gene mutation is inherited; however, the majority of tumors are sporadic and not inherited.

Treatment is with surgery. Patients who have disease that has spread are treated with surgery when possible and with imatinib mesylate (Gleevec, Glivec), a tyrosine kinase inhibitor that inhibits the KIT or PDGFR responsible for tumor growth. Ongoing studies are testing to see if imatinib mesylate can delay or prevent recurrence of GIST after the tumor has been removed (resection). Standard chemotherapy is not effective for this type of sarcoma, with a less than 5% response rate. The role of imatinib mesylate in pediatric GIST is being studied at this time.

What are the symptoms for gastrointestinal stromal tumors?

Small GISTs may cause no symptoms, and they may grow so slowly that they don't cause problems at first. As a GIST grows, it can cause signs and symptoms. They might include:

  • Abdominal pain
  • A growth you can feel in your abdomen
  • Fatigue
  • Nausea
  • Vomiting
  • Cramping pain in the abdomen after eating
  • Not feeling hungry when you would expect to
  • Feeling full if you eat only a small amount of food
  • Dark-colored stools caused by bleeding in the digestive system

What are the causes for gastrointestinal stromal tumors?

In most cases, it's not clear what causes soft tissue sarcoma.

In general, cancer occurs when cells develop errors (mutations) in their DNA. The errors make cells grow and divide out of control. The accumulating abnormal cells form a tumor that can grow to invade nearby structures and the abnormal cells can spread to other parts of the body.

The type of cell that develops the genetic mutation determines what type of soft tissue sarcoma you have. For example, angiosarcoma begins in the lining of blood vessels, while liposarcoma arises from fat cells. Some types of soft tissue sarcoma include:

  • Angiosarcoma
  • Dermatofibrosarcoma protuberans
  • Epithelioid sarcoma
  • Gastrointestinal stromal tumor (GIST)
  • Kaposi's sarcoma
  • Leiomyosarcoma
  • Liposarcoma
  • Malignant peripheral nerve sheath tumor
  • Myxofibrosarcoma
  • Rhabdomyosarcoma
  • Solitary fibrous tumor
  • Synovial sarcoma

What are the treatments for gastrointestinal stromal tumors?

Your treatment options for soft tissue sarcoma will depend on the size, type and location of your tumor.

Surgery

Surgery is a common treatment for soft tissue sarcoma. Surgery generally involves removing the cancer and some healthy tissue surrounding it.

When soft tissue sarcoma affects the arms and legs, radiation and chemotherapy may be considered to shrink the tumor to avoid amputation.

Radiation therapy Intraoperative radiation therapy Open pop-up dialog box Close Intraoperative radiation therapy Intraoperative radiation therapy

During intraoperative radiation therapy (IORT), radiation is directed through the surgical incision onto a specific site. The dose of IORT can be much higher than is possible with standard radiation therapy given from the outside of the body.

Radiation therapy involves treating cancer with high-powered beams of energy. Options include:

  • Before surgery. Radiation before surgery can help shrink the tumor so that it's easier to remove.
  • During surgery. Intraoperative radiation allows a higher dose of radiation to be delivered directly to the target area, while sparing surrounding tissues.
  • After surgery. Postoperative radiation can help kill any remaining cancer cells.

Chemotherapy

Chemotherapy is a drug treatment that uses chemicals to kill cancer cells. Chemotherapy can be administered by pill or through a vein (intravenously). Some forms of soft tissue sarcoma respond better to chemotherapy than do others. For instance, chemotherapy is often used to treat rhabdomyosarcoma.

Targeted drug treatment

Some types of soft tissue sarcoma have specific characteristics in their cells that can be attacked via targeted drug treatments. These medicines work better than chemotherapy and aren't nearly as toxic. Targeted treatments have been particularly helpful in gastrointestinal stromal tumors (GISTs).

What are the risk factors for gastrointestinal stromal tumors?

Factors that may increase your risk of sarcoma include:

  • Inherited syndromes. A risk of soft tissue sarcoma can be inherited from your parents. Genetic syndromes that increase your risk include hereditary retinoblastoma, Li-Fraumeni syndrome, familial adenomatous polyposis, neurofibromatosis, tuberous sclerosis and Werner syndrome.
  • Chemical exposure. Being exposed to certain chemicals, such as herbicides, arsenic and dioxin, may increase the risk of soft tissue sarcomas.
  • Radiation exposure. Previous radiation treatment for other cancers can increase the risk of soft tissue sarcomas.

Is there a cure/medications for gastrointestinal stromal tumors?

The digestive system of the body includes the gastrointestinal (GI) tract. In order for the body to utilize the nutrients (vitamins, minerals, carbs, fats, proteins, and water) from food, it aids in digestion. A condition known as gastrointestinal stromal tumor causes abnormal cells to grow in the tissues of the gastrointestinal or digestive tract.

Cure/medications:

  • Patients with gastrointestinal stromal tumors can choose from a variety of treatments (GISTs). Clinical trials are being conducted to test various treatments, some of which are standard (currently used treatments).
  • A clinical trial for treatment is a research project designed to find out more about potential new treatments for cancer patients or to assist enhance existing treatments.
  • A new treatment might replace the standard one if clinical trials reveal that it is superior to the current one.
  • Only patients who have not begun treatment are allowed to participate in some clinical trials.
  • Surgery: The tumor and a margin or boundary of the surrounding healthy tissue are removed during surgery. If it is possible, this is the major treatment for GISTs.
  • Targeted drugs: Drugs that target specific alterations in cancer cells that promote growth target these changes. These medications primarily impact cancer cells in the body, not healthy cells. If surgery is not an option, they are frequently the primary form of treatment for GISTs.


Conditions
GI hemorrhage,GI obstruction,Bowel perforation
Drugs
Sorafenib (Nexavar),Nilotinib (Tasigna),Dasatinib (Sprycel),Pazopanib (Votrient)
Symptoms
Blood in the stool or vomit, either bright red or very dark,Abdominal pain, which could be really bad,Feeling incredibly exhausted,Difficulty or discomfort swallowing,Feeling full after consuming only a small amount of food

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