The gastrointestinal tract includes the stomach, small intestine, and large intestine. These organs are part of the digestive system, which processes the food we eat and passes waste out of the body.
Gastrointestinal carcinoid tumors develop from a certain type of cell in the lining of the gastrointestinal tract. These cells produce hormones that help regulate digestive juices and the muscles used to move food through the stomach and intestines.
Gastrointestinal carcinoid tumors begin when a normal cell becomes abnormal. Normal cells grow and divide to form new cells as the body needs them. When normal cells grow old or get damaged, they die, and new cells take their place. Sometimes this process goes wrong. New cells form when the body doesn't need them, and old or damaged cells don't die as they should. The buildup of extra cells often forms a mass of tissue called a growth or tumor. Tumors can be benign (not cancer) or malignant (cancer).
Gastrointestinal carcinoid tumors grow slowly. Most of them occur in the appendix (a small organ attached to the large intestine), small intestine, and rectum.
The source for this information is the National Cancer Institute.
Doctors can't always explain why one person gets cancer and another doesn't. However, certain risk factors make a person more likely than others to develop gastrointestinal carcinoid tumors. A risk factor is something that may increase the chance of getting a disease.
Having a risk factor does not mean a person will get cancer. Many people who get gastrointestinal carcinoid tumors have no risk factors, and many people who have known risk factors never get cancer. A person with one or more of these risk factors should talk with his or her doctor about cancer risk.
These are risk factors for gastrointestinal carcinoid tumors:
- Multiple endocrine neoplasia type 1 (MEN1) syndrome: People who have a family history of MEN1 syndrome have a higher risk of developing gastrointestinal carcinoid tumors.
- Conditions that affect the production of stomach acid: People who have conditions that affect the stomach's ability to produce stomach acid (such as atrophic gastritis, pernicious anemia, or Zollinger-Ellison syndrome) have a higher risk of gastrointestinal carcinoid tumors.
- Smoking: People who smoke are more likely than people who don't smoke to develop gastrointestinal carcinoid tumors.
A gastrointestinal carcinoid tumor often has no symptoms in its early stages. As the cancer grows, the hormones produced by gastrointestinal carcinoid tumors may cause the following group of symptoms (called carcinoid syndrome):
- Fast heartbeat
- Pain or a feeling of fullness in the abdomen
- Redness or a feeling of warmth in the face and neck
- Shortness of breath
- Swelling of the feet and ankles
Most often, these symptoms do not mean cancer. A person with these symptoms should tell his or her doctor so any health problems can be diagnosed and treated as early as possible.
Currently, there are no screening methods for gastrointestinal carcinoid tumors.
If symptoms suggest a gastrointestinal carcinoid tumor, the doctor will try to find out what's causing the problems. The doctor may order one or more of the following tests:
- Physical exam and history: The doctor will check for signs of disease, such as high blood pressure, lumps, or anything else that seems unusual.
- Blood tests: The doctor sends blood to the lab to check the number of blood cells and to measure the amounts of certain substances, such as hormones, released into the blood by organs and tissues in the body. A higher or lower than normal amount of a substance can be a sign of disease. The blood sample is checked to see if it contains a hormone produced by carcinoid tumors.
- Urine tests: The lab checks the urine for hormones produced by carcinoid tumors. This test is used to help diagnose carcinoid syndrome.
If a gastrointestinal carcinoid tumor is diagnosed, the doctor needs to learn the extent (stage) of the disease to help choose the best treatment. Staging is a careful attempt to find out whether the cancer has spread, and if so, to what parts of the body
The doctor may order one or more of these staging tests:
- Gastrointestinal endoscopy: Endoscopy looks at the inside of the gastrointestinal tract for abnormal areas or cancer. The doctor passes a thin, lighted tube (endoscope) through the mouth to look at the esophagus, stomach, and part of the small intestine. The doctor may also use a thin, lighted tube (colonoscope) inserted through the rectum to look at the colon.
- CT scan: An x-ray machine linked to a computer takes a series of detailed pictures of the inside of the body. The patient may receive contrast material by mouth or by injection into a blood vessel. The contrast material makes abnormal areas easier to see.
- Somatostatin receptor scintigraphy (SRS): The doctor injects a drug called radioactive octreotide into a vein. The radioactive octreotide attaches to carcinoid tumor cells that have somatostatin receptors. A radiation-measuring device detects the radioactive material, showing where the carcinoid tumor cells are in the body. This procedure is also called an octreotide scan.
- Biopsy: The doctor removes tissue from the body and sends it to a lab. Tissue samples may be taken during an endoscopy. The doctor in the lab looks at the tissue under a microscope for signs of cancer.
- Angiogram: The doctor injects a contrast dye into a blood vessel. As the contrast dye moves through the blood vessel, x-rays are taken to see if there are any blockages.
- PET scan: The patient receives an injection of a small amount of radioactive sugar. The radioactive sugar gives off signals that the PET scanner picks up. The PET scanner makes pictures of the sugar used by cells in the body. Cancer cells use sugar faster than normal cells so areas with cancer look brighter on the pictures.
- X-ray of the abdomen: An x-ray of the organs and tissues inside the abdomen can reveal signs of cancer.
Stages of Gastrointestinal Carcinoid Tumors
There are two different ways that gastrointestinal carcinoid tumors can be staged; a general three-stage system or a system tailored to the part of the body where the cancer is found. The general three-stage system is described below:
Localized: Cancer is found in one organ only.
Regional: Cancer has spread to nearby tissues or lymph nodes.
Metastatic: Cancer has spread to other parts of the body.
There are more detailed staging systems used for carcinoid tumors of the stomach, small intestine, colon, rectum, and appendix. Patients diagnosed with carcinoid tumors in these parts of the body should talk with their doctor to find out the stage.
At Huntsman Cancer Institute, gastrointestinal carcinoid tumors are treated by a team of specialists, including gastroenterologists (doctors who specialize in treating problems of the digestive organs), surgeons, medical oncologists (doctors who treat cancer with medicine), radiation oncologists (doctors who treat cancer with radiation), nurses, dietitians, and social workers.
These are common treatment options for gastrointestinal carcinoid tumors:
- Radiation therapy
- Percutaneous ethanol injection
- Biological therapy
- Hormone therapy
- Other drug therapy
- Clinical trials
A patient may have a combination of treatments. The treatment that's right for each patient depends on many factors:
- The location and size of the cancer
- Where the tumor is in the gastrointestinal tract
- Whether the cancer can be completely removed by surgery
- Whether the cancer has spread to other parts of the body
- The patient's symptoms
- The patient's age and general health
The health care team can describe all of the treatment choices, the expected results of each, and the possible side effects. Because cancer therapy often damages healthy cells and tissues, side effects are common. Side effects may not be the same for each person, and they may even change from one treatment session to the next. Patients are encouraged to discuss treatment side effects with their health care team.
Treatment of gastrointestinal carcinoid tumors usually includes surgery. The type of surgery used depends mainly on where the cancer is located. One of the following surgical procedures may be used to treat gastrointestinal carcinoid tumors:
- Appendectomy: A surgeon removes the appendix.
- Bowel resection and anastomosis: A surgeon removes a tumor in the bowel and a small section of healthy bowel on each side. The healthy parts of the bowel are then sewn together (called anastomosis). Lymph nodes are removed and checked to see if they contain cancer.
- Cryosurgery (cryotherapy): The doctor uses a special instrument to freeze and destroy the cancer.
- Fulguration: The doctor uses a special tool with an electric current to burn away the tumor.
- Hepatic artery ligation or embolization: These procedures ligate (tie off) or embolize (block) the hepatic artery, the main blood vessel that brings blood into the liver. Blocking the flow of blood to the liver helps kill cancer cells growing there.
- Hepatic resection: A surgeon removes all or part of the liver.
- Radiofrequency ablation: A doctor uses a special probe with tiny electrodes that release high-energy radio waves (similar to microwaves) that kill cancer cells. The probe may be inserted through the skin or through an incision (cut) in the abdomen.
- Resection: A surgeon removes all or part of the organ that contains cancer.
Chemotherapy uses drugs to kill and control cancer cells. Chemotherapy can be given by mouth, injected into a vein, or injected directly into the liver (chemoembolization).
Learn more about this treatment in our introduction to chemotherapy video.
Radiation therapy uses high-energy rays to kill cancer cells. Radiation therapy only affects cells in the treated area.
Two types of radiation therapy are used to treat cancer. Some patients receive both types:
- External radiation: The radiation comes from a large machine outside the body. The machine aims beams of radiation at the cancer. Patients go to a hospital or clinic for treatment. This type of treatment uses computers to closely target the cancer, which protects healthy tissue.
- Internal radiation therapy (brachytherapy): The radiation comes from radioactive material usually contained in very small implants called seeds. The seeds are put near or directly into the cancer, using thin plastic tubes.
Percutaneous ethanol injection is a cancer treatment in which the doctor uses a small needle to inject ethanol (alcohol) directly into a tumor to kill cancer cells.
Biological therapies help the body's immune system fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body's natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.
Hormones are substances produced by glands in the body and circulated in the bloodstream. The presence of some hormones can cause certain cancers to grow. Hormone therapy is a cancer treatment that removes hormones or blocks their action and stops cancer cells from growing. If tests show that the cancer cells have places where hormones can attach (receptors), drugs, surgery, or radiation therapy are used to reduce the production of hormones or block them from working.
The drug MIBG (metaiodobenzylguanidine) is sometimes used, with or without radioactive iodine (I131), to lessen the symptoms of gastrointestinal carcinoid tumors.
These studies discover and evaluate new and improved cancer treatments. Patients are encouraged to talk with their doctors about participating in a clinical trial or any questions regarding research studies. For more information, also visit HCI's clinical trials website.
When you or someone you love is diagnosed with cancer, concerns about treatments and side effects, hospital stays, and medical bills are common. You may also worry about caring for your family, work, or normal daily life.
There are several places you can go for support:
- Your health care team can answer your questions and talk to you about your concerns. They can help you with any side effects and keep you informed of all your treatments, test results, and future doctor visits.
- Our Patient and Family Support Services offer emotional support and resources for coping with cancer and its impact on daily life to HCI patients and their families.
- The Linda B. and Robert B. Wiggins Wellness-Survivorship Center offers many programs to increase the quality of life and well-being of HCI patients and their families.
Make an Appointment
Gastrointestinal Cancer Program
Did You Know?
- A gastrointestinal carcinoid tumor often has no symptoms in its early stages.
- Most gastrointestinal carcinoid tumors occur in the appendix, the small intestine, or the rectum.
- Gastrointestinal carcinoid tumors can cause a group of symptoms called carcinoid syndrome.