Gastrointestinal stromal tumors (GISTs) are rare cancers that develop in the digestive tract, primarily in the stomach and small intestine. They originate from mutated interstitial cells of Cajal, which are specialized nerve cells involved in moving food through the digestive tract. GISTs are most commonly diagnosed in individuals over 50 and can initially appear benign, though larger tumors often become malignant and can spread to other areas. Symptoms of GISTs may not be evident until the tumor grows larger, potentially causing abdominal pain, blood in stools, nausea, and fatigue. Risk factors include age, genetic disorders like Neurofibromatosis type 1, and a family history of GISTs. Most GISTs are linked to mutations in the KIT gene, leading to uncontrolled cell growth. Diagnosis involves imaging tests, endoscopy, and biopsies, with tumors staged based on size, growth rate, and spread. Treatment options include surgery, targeted drug therapies, and less commonly, chemotherapy or ablation techniques. Prognosis depends on early detection and tumor stage, with a better outlook for smaller, localized tumors.
A gastrointestinal stromal tumour, also known as gastrointestinal stromal sarcoma, is a rare, cancerous tumour that grows in the digestive tract. They occur most often in the stomach or the small intestine. In rare cases, the tumour can also grow on the peritoneum (membrane around the abdominal cavity) or the omentum (a layer of fatty tissue that envelops the abdominal organs). Gastrointestinal stromal tumours are thought to form as a result of the mutation of a specific type of nerve cells, called interstitial cells of Cajal, found in the walls of the digestive system. The function of these special nerve cells is to move the food through the digestive tract correctly. Gastrointestinal stromal tumours can affect people of any age, but are very rare in children and young adults. Small gastrointestinal stromal tumours may not cause any symptoms. Depending on the rate of growth, some gastrointestinal stromal tumours can appear benign at first. However, as they grow larger, they become malignant and can metastasize or spread to other parts of the body.
Gastrointestinal stromal tumours often only start causing symptoms when they are larger. The symptoms include:
These symptoms could also indicate other medical conditions which aren’t cancerous. If you experience any of these symptoms, visit your gastroenterologist for a check-up.
People older than 50 years have the highest risk of developing gastrointestinal stromal tumours. People with pre-existing rare genetic conditions like Neurofibromatosis type 1 or Carney-Stratakis syndrome also face a higher risk. Having a family history of gastrointestinal stromal tumours increases the risk of developing these tumours at a younger age. Having said that, a higher risk factor doesn’t mean you will develop the condition. Many patients who have gastrointestinal stromal tumours have none of these risk factors.
Gastrointestinal stromal tumours are usually formed when a KIT gene mutates. This causes cells in the digestive tract to multiply at an uncontrolled rate. The KIT gene helps cells make the KIT CD 117 protein, causing cell division. The abnormal cells multiply and develop into gastrointestinal stromal tumours. Science still has no clear answers about what triggers the KIT gene mutation.
Small gastrointestinal stromal tumours often don’t cause any symptoms. These are usually discovered during routine health checkups or scans to investigate other medical conditions the patient may have. Large tumours or groups of tumours will cause symptoms, although the symptoms are not conclusive evidence of gastrointestinal stromal tumours in particular. The doctor will conduct further investigations based on a physical exam, a patient medical history and an account of their symptoms. A panel of blood tests and liver functions tests are usually also performed, to assess the patient’s baseline health.
The doctor will usually begin with imaging tests to check for any abnormalities in the gastrointestinal tract. An ultrasound scan or a CT scan may be performed. The results from these tests will provide evidence of tumours or any structural changes to the abdominal organs. Then the gastroenterologist may perform an upper endoscopy, to get a closer look at the tumours. This is a test in which a long thin tube, with a camera on the end of it, is inserted into the mouth, and navigated through the throat, oesophagus, stomach and small intestine. An endoscopic ultrasound may also be performed to determine the exact size and shape of the tumour. A fine-needle biopsy is usually performed to confirm the type of tumour cells that are growing uncontrollably. A small sample of the tumour is obtained through a needle and sent to a pathology lab for detailed investigation. A PET scan may also be performed to check whether the cancer has spread to other parts of the body.
Gastrointestinal stromal tumours are classified according to tumour size, growth rate and the extent to which the cancer has spread to surrounding lymph nodes and other organs. Based on this information, doctors can categorize the tumours into 4 stages –
Stage 1 – The tumour is small, and growing slowly. It usually has not yet spread to surrounding lymph nodes or other organs.
Stage 2 – The tumour is larger, and may be growing. However, it has still not metastasized to other body parts
Stage 3 – The tumour is large, and growing quickly. It has still not spread to the rest of the body.
Stage 4 – The tumour is large and has metastasized.
The staging of gastrointestinal tumours is a complex classification system. Tumours originating in the stomach and omentum are classified according to a different stage grouping scheme than tumours originating in any other part of the digestive tract. This is because tumours that start growing in the stomach and omentum are least likely to spread. You can consult your oncologist for further details about the stage that your gastrointestinal tumours are at and what to expect going forward.
A team of specialists form a multi-disciplinary team, to devise a treatment plan for gastrointestinal stromal tumours. The treatment plan depends on the location and size of the tumour(s), the patient’s general health, the growth rate of the tumour(s) and the genetic changes in the tumour cells. Treatment often involves targeted therapies to shrink the tumour(s) and surgical removal. Some gastrointestinal tumours do not need treatment right away. In case of very small tumours that aren’t causing any symptoms, doctors may choose to perform tests to check their growth rate over time, and only treat them once larger. They grow some of the main treatment methods for gastrointestinal stromal tumours are:
Surgical Removal – The goal of surgery is to remove the entire tumour, along with a comfortable margin of surrounding tissue. This is done to reduce chances of the tumour growing back. This is often the most preferred treatment for gastrointestinal stromal tumours that haven’t metastasized yet. Small tumours can be removed using minimally-invasive techniques. The tumour removal procedure is performed through a small incision, using precision tools. The patient loses less blood, and suffers less collateral trauma as a result of this, allowing them to recover faster. For slightly larger tumours, the surgeon may opt to perform a local wide excision. In this case, the tumour is removed along with a margin of surrounding tissue in an open surgical procedure.
Larger tumours that encroach into the wall of the digestive tract require part of the stomach or small intestine to be removed. This is known as a partial gastrectomy or partial intestine resection respectively. Surgery can cure the patient completely when the tumour is still small. With larger tumours, this is not always a certainty, as there are chances the tumour will grow back.
Targeted drug therapy – Targeted drug therapies work on blocking specific chemicals present in the cancer cells, causing them to wither and die. They usually target an enzyme called tyrosine kinase. The targeted drug therapy may be given before surgery, to shrink the tumour and make it easier to operate on. The medication may also be given after surgery to lower the chance of recurrence. Targeted drug therapies are an area of active medical research, and new drugs are likely to become available in the future.
Chemotherapy – Chemotherapy drugs are strong medicines used to kill cancer cells. The medication is often given to the patient through an IV, although some chemotherapy drugs are available in pill form as well. One of the main advantages of chemotherapy is its ability to treat metastatic cancer, i.e. cancer that has spread. However, as targeted drug therapy has been shown to be more effective at shrinking gastrointestinal stromal tumours, chemotherapy is used less often. This is also due to the extreme side effects caused by chemotherapy. This includes hair loss, nausea, diarrhea, vomiting, loss of appetite, fatigue and an increased chance of infection.
Ablation – Ablation is a minimally-invasive procedure to destroy tumour cells using extremes of temperature or chemicals. This technique is often used to treat small metastasized tumours on the liver. Ablation has a tendency to destroy the tissue surrounding the tumour too, so it isn’t recommended for tumours that are close to important structures like major blood vessels. During the ablation procedure, a small catheter is inserted into a small incision in an artery and threaded to the location of the tumour. Then, a small probe is inserted into the catheter. The probe emits radio frequency waves or microwaves that generate heat and kill the tumour cells. A cryoprobe may also be used, to freeze the tumour cells and destroy them. Sometimes, ethanol is injected into the tumour to kill it.
Embolization – Embolization is a procedure that cuts off the tumours blood supply. This deprives the tumour cells of oxygen and other nutrients and inhibits their growth. This procedure is known as trans arterial embolisation or TAE. A catheter is inserted into an incision in the femoral artery and guided to the tumor’s vascular network. A contrast dye is usually injected at this stage, to provide high quality images on the real-time X-ray machine used to locate the tumour. Once the catheter is in place, the surgeon injects tiny particles into the artery. The particles set in place like superglue and seal the blood vessel.
The patient’s long-term outlook depends on which stage the gastrointestinal tumours were diagnosed at. It also depends on their general health, and ability to withstand surgery. It is important for patients to eat healthy, drink lots of water, get moderate levels of exercise and avoid tobacco products of any kind. The diagnosis and treatment can be overwhelming, but surrounding yourself with friends and family, as well as seeing a counsellor, could help keep the patient’s spirits up and motivated.
If you or a loved one are experiencing symptoms of gastrointestinal stromal tumours or have concerns about digestive health, expert diagnosis and advanced treatment are available at Kauvery Hospital. With branches in Chennai, Hosur, Salem, Tirunelveli, and Trichy, our team of specialists is dedicated to providing comprehensive care and support at every stage of your journey.
What are Gastrointestinal Stromal Tumours (GISTs)?
Gastrointestinal stromal tumours are rare cancers that develop in the digestive tract—most often in the stomach or small intestine. They begin from the interstitial cells of Cajal, which help move food through the digestive system.
What are the common symptoms of GISTs?
Many GISTs cause no early symptoms. As the tumour grows, symptoms like abdominal pain, blood in stools, fatigue, nausea, vomiting, and unexplained weight loss may occur.
How are GISTs diagnosed?
Doctors use imaging tests such as CT or MRI scans, followed by endoscopy and biopsy, to confirm a GIST diagnosis and determine if it’s benign or malignant.
What causes Gastrointestinal Stromal Tumours?
Most GISTs occur due to a mutation in the KIT gene, leading to uncontrolled cell growth. However, the exact reason for this mutation is still unclear.
What are the treatment options for GISTs?
Treatment may include surgery, targeted drug therapy, or minimally invasive techniques like ablation or embolisation, depending on tumour size, growth rate, and spread.
Kauvery Hospital is globally known for its multidisciplinary services at all its Centers of Excellence, and for its comprehensive, Avant-Grade technology, especially in diagnostics and remedial care in heart diseases, transplantation, vascular and neurosciences medicine. Located in the heart of Trichy (Tennur, Royal Road and Alexandria Road (Cantonment), Chennai (Alwarpet, Radial Road & Vadapalani), Hosur, Salem, Tirunelveli and Bengaluru, the hospital also renders adult and paediatric trauma care.
Chennai Alwarpet – 044 4000 6000 • Chennai Radial Road – 044 6111 6111 • Chennai Vadapalani – 044 4000 6000 • Trichy – Cantonment – 0431 4077777 • Trichy – Heartcity – 0431 4003500 • Trichy – Tennur – 0431 4022555 • Hosur – 04344 272727 • Salem – 0427 2677777 • Tirunelveli – 0462 4006000 • Bengaluru – 080 6801 6801
