Your 5-Minute Guide to GISTs

GISTs (gastrointestinal stromal tumours) seem to be on the rise in the Indian population. Keep reading to know about its causes, symptoms, diagnosis and treatment.

What is a GIST?

A GIST (gastrointestinal stromal tumour) is a rare type of tumour that originates in the gastrointestinal tract (GIT), most commonly from the stomach or small intestine. It arises from special types of nerve cells in the GIT.

Are GISTs cancerous?

Not necessarily. These may either be benign (non-cancerous) or malignant (cancerous).

Is GIST a type of stomach cancer?

No, it is not the same as stomach cancer. Ordinary stomach cancer belongs to a group of cancers called adenocarcinoma which develop from the gland cells, while malignant GIST tumours are classified as sarcomas. They originate from different cells and therefore have different treatments.

What causes GIST?

These occur due to mutations in the KIT oncogene, a gene responsible for making proteins called receptor tyrosine kinases. These mutations may be spontaneous or hereditary.

Am I at risk for developing a GIST?

Most cases develop spontaneously, without a clear reason. However, you can be at a risk for developing them if you have someone in your family suffering from-

Familial GIST syndrome
Neurofibromatosis type 1
Carney-Stratakis syndrome

How can I lower my risk of getting GIST?

There are no lifestyle-related factors that determine your chances of getting this disease. Consult your doctor if anyone in your family has GIST or any genetic conditions related to it.

What are some of the symptoms of GIST?

Initially, you may not experience any symptoms. As the disease progresses, you may notice –

Blood in the vomit or stools
Abdominal pain
Fatigue
Nausea and vomiting
Feeling full despite eating less or not feeling hungry at all

How is GIST diagnosed?

Your doctor will ask you about your symptoms in detail and also examine you physically. They can recommend the following tests for confirming the diagnosis and staging the disease –

Imaging: Your doctor can advise you to get an ultrasound, CT scan, MRI scan or a PET scan
Upper endoscopy: A long thin tube with an attached camera is inserted through your mouth to look at the insides of your GIT
Biopsy: Your doctor will take a small piece of the tumour and perform various tests to get detailed information about the tumour

Why does my doctor want me to undergo genetic testing?

Your doctor can perform genetic testing on your biopsy sample to detect the underlying mutations. This also helps them in predicting how the cancer can progress, and what the right treatment is.

How is GIST treated?

Not all tumours need to be immediately treated. In case of small tumours, your doctor may recommend you to wait and watch. In other cases, your doctor will discuss these treatment options with you –

Surgery – Your doctor can advise surgery if the tumour has not spread to other parts. The main goal is to get rid of the entire tumour.
Targeted therapy – Standard chemotherapy is not very effective. In targeted therapy, the drugs specifically attack the cancer cells while leaving the normal cells unharmed. TKIs (tyrosine kinase inhibitors) are specifically used for treatment. They inhibit a specific protein called tyrosine kinase in the cancer cells.

What are the side effects of targeted therapy?

You may experience –

Nausea and vomiting
Constipation or diarrhoea
Decreased blood counts
Fatigue
Muscle cramps
Skin and hair colour changes

What should I do post-treatment?

After treatment, you will be required to regularly follow up and watch out for any changes or recurrence.

In case of post-surgery, you may have to undergo a CT scan and look out for any symptoms
In case of post-targeted therapy, your doctor will advise you to get a CT, MRI, or PET scans

Are these treatments curative?

Due to medical advancements, the chances of survival have drastically improved over the years. For resectable tumours, surgery is the best treatment choice. For patients who cannot undergo surgery, targeted therapies can help shrink the tumour and prevent it from spreading.

How can I cope with a GIST?

It can be scary and overwhelming to get an unfavourable diagnosis. You can use the following strategies to cope –

Learning as much as you can about the disease, how it progresses, its symptoms and management
Reaching out to your loved ones for support
Keeping a positive attitude
Staying healthy by eating a balanced diet, regularly exercising and getting enough sleeping

What is my prognosis?

Your prognosis depends on the size, location, and rate at which the tumour cells are spreading. All patients, even those with low-risk disease, should routinely undergo check-ups to prevent recurrence.