Gastrointestinal stromal tumor or GIST is a rare type of tumor of the gastrointestinal tract that initially presents no symptoms, but as the tumor grows it can cause symptoms such as vomiting or bloody stools, abdominal pain or a feeling of being full even after have eaten little.
This tumor can be benign or malignant and originates from the interstitial cells of Cajal that line the wall of any part of the gastrointestinal tract and are responsible for bowel movements, most frequently affecting the stomach or small intestine, but can also occur in the esophagus, colon or straight, for example.
The treatment of GIST (from English Gastrintestinal Stromal Tumors) is performed by the oncologist and varies according to the size of the tumor, its extension and stage, and follow-up with exams, surgery or targeted therapy may be indicated.
Symptoms of GIST
The main symptoms of GIST or gastrointestinal stromal tumor are:
- Vomiting with blood, similar to coffee grounds;
- Dark, black, reddish or bright bloody stools;
- Constant nausea and loss of appetite;
- Abdominal pain or swelling;
- Constant feeling of being full, even after having eaten little;
- Weight loss for no apparent reason;
- Difficulty swallowing, in the case of GIST in the esophagus.
Furthermore, other symptoms that may arise are tiredness or frankness, due to gastrointestinal bleeding, which can result in anemia.
If symptoms such as vomiting and severe abdominal pain appear, you should go to the hospital immediately, as they are indicative of stomach or intestinal obstruction, which are medical emergencies that require immediate care.
How to confirm the diagnosis
The initial diagnosis of GIST, or gastrointestinal stromal tumor, is normally made by a general practitioner or gastroenterologist, through evaluation of symptoms, health history and physical examination.
If the doctor feels a palpable solid mass, he or she should request a computed tomography with contrast, and in cases of people allergic to contrast, an MRI is performed. Other tests that may be requested are endoscopy, colonoscopy and PET-CT. See how PET-CT is done.
In addition, the doctor must request a biopsy of the tumor, obtained through fine needle aspiration or during surgery, and immunohistochemical and genetic tests, to confirm the diagnosis, stage and type of tumor, and thus refer the person to treatment with the oncologist.
Make an appointment with an oncologist in the nearest region:
How do you know if GIST is malignant or benign?
The way to know whether it is malignant or benign is through tests ordered by the doctor, a biopsy of the tumor and immunohistochemical tests.
Most GISTs are benign, showing slow growth and measuring less than 2 cm, however, depending on their size and cell multiplication capacity, they can be malignant, that is, cancer.
In this case, when it is malignant, GIST is part of a group of cancers called soft tissue sarcomas. Understand what sarcoma is.
Possible causes
GIST is caused by mutations in the KIT (CD 117) or PDGFRA (platelet-derived growth factor alpha receptor) genes, resulting in the uncontrolled multiplication of the interstitial cells of Cajal that line the wall of the gastrointestinal tract.
Some factors can increase the risk of developing GIST, such as:
- Age, being more common after age 60;
- Familial gastrointestinal stromal tumor syndrome (GIST);
- Carney syndrome;
- Type 1 neurofibromatosis.
Generally, GIST grows slowly, however, it has malignant potential and can become cancer, and can often be diagnosed in routine exams, especially when the person does not present symptoms in its initial stages.
In the case of people who have familial gastrointestinal stromal tumor syndrome, it is important to see an oncologist regularly so that the tumor is detected early.
How the treatment is carried out
GIST treatment must be carried out under the guidance of an oncologist, and varies according to the size of the tumor and the extent of the disease.
For tumors smaller than 2 cm and that do not cause symptoms, monitoring of the tumor through endoscopic ultrasound, performed 1 or 2 times a year, may be recommended.
For tumors larger than 2 cm, which have not spread and are capable of being removed, surgery is recommended by the doctor, and treatment with targeted therapy, such as imatinib, can also be carried out before surgery to reduce the size. size of the tumor or after surgery to complement treatment.
In cases of metastases, in which the tumor has spread to other parts of the body, or tumors that cannot be removed by surgery, treatment is usually done with targeted therapy, with drugs such as imatinib, sunitinib, sorafenib, Pazopanib, regorafenib, ripretinib , dasatinib, nilotinib or Pazopanib, for example. If the tumor shrinks, it may be indicated in some cases.
