Summary

Key Points

• A gastrointestinal carcinoid tumor is cancer that forms in the lining of the gastrointestinal tract.
• Health history can affect the risk of gastrointestinal carcinoid tumors.
• Some gastrointestinal carcinoid tumors have no signs or symptoms in the early stages.
• Carcinoid syndrome may occur if the tumor spreads to the liver or other parts of the body.
• Imaging studies and tests that examine the blood and urine are used to detect (find) and diagnose gastrointestinal carcinoid tumors.
• Certain factors affect prognosis (chance of recovery) and treatment options.

A gastrointestinal carcinoid tumor is cancer that forms in the lining of the gastrointestinal tract.

The gastrointestinal (GI) tract is part of the body’s digestive system. It helps to digest food, takes nutrients (vitamins, minerals, carbohydrates, fats, proteins, and water) from food to be used by the body and helps pass waste material out of the body. The GI tract is made up of these and other organs:

• Stomach.
• Small intestine (duodenum, jejunum, and ileum).
• Colon.
• Rectum.

Gastrointestinal carcinoid tumors form from a certain type of neuroendocrine cell (a type of cell that is like a nerve cell and a hormone -making cell). These cells are scattered throughout the chest and abdomen but most are found in the GI tract. Neuroendocrine cells make hormones that help control digestive juices and the muscles used in moving food through the stomach and intestines. A GI carcinoid tumor may also make hormones and release them into the body.

GI carcinoid tumors are rare and most grow very slowly. Most of them occur in the small intestine, rectum, and appendix. Sometimes more than one tumor will form.

See the following PDQ summaries for more information related to GI and other types of carcinoid tumors:

• Non-Small Cell Lung Cancer Treatment.
• Pancreatic Neuroendocrine Tumors (Islet Cell Tumors) Treatment.
• Rectal Cancer Treatment.
• Small Intestine Cancer Treatment.
• Unusual Cancers of Childhood Treatment

Risk Factors

Health history can affect the risk of gastrointestinal carcinoid tumors.

Anything that increases a person’s chance of developing a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. Talk to your doctor if you think you may be at risk.

Risk factors for GI carcinoid tumors include the following:

• Having a family history of multiple endocrine neoplasia type 1 (MEN1) syndrome or neurofibromatosis type 1 (NF1) syndrome.
• Having certain conditions that affect the stomach’s ability to make stomach acid, such as atrophic gastritis, pernicious anemia, or Zollinger-Ellison syndrome.

Screening and Detection

Imaging studies and tests that examine the blood and urine are used to detect (find) and diagnose gastrointestinal carcinoid tumors.

The following tests and procedures may be used:

• Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
• Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances, such as hormones, released into the blood by organs and tissues in the body. An unusual (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. This test is used to help diagnose carcinoid syndrome.
• Tumor marker test: A procedure in which a sample of blood, urine, or tissue is checked to measure the amounts of certain substances, such as chromogranin A, made by organs, tissues, or tumor cells in the body. Chromogranin A is a tumor marker. It has been linked to neuroendocrine tumors when found in increased levels in the body.
• Twenty-four-hour urine test: A test in which urine is collected for 24 hours to measure the amounts of certain substances, such as 5-HIAA or serotonin (hormone). An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it. This test is used to help diagnose carcinoid syndrome.
• MIBG scan: A procedure used to find neuroendocrine tumors, such as carcinoid tumors. A very small amount of radioactive material called MIBG (metaiodobenzylguanidine) is injected into a vein and travels through the bloodstream. Carcinoid tumors take up the radioactive material and are detected by a device that measures radiation.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
• MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging
• PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells.
• Endoscopic ultrasound (EUS): A procedure in which an endoscope is inserted into the body, usually through the mouth or rectum. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. A probe at the end of the endoscope is used to bounce high-energy sound waves (ultrasound) off internal tissues or organs, such as the stomach, small intestine, colon, or rectum, and make echoes. The echoes form a picture of body tissues called a sonogram. This procedure is also called endosonography.
• Upper endoscopy: A procedure to look at organs and tissues inside the body to check for abnormal areas. An endoscope is inserted through the mouth and passed through the esophagus into the stomach. Sometimes the endoscope also is passed from the stomach into the small intestine. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue or lymph node samples, which are checked under a microscope for signs of disease.
• Colonoscopy: A procedure to look inside the rectum and colon for polyps, abnormal areas, or cancer. A colonoscope is inserted through the rectum into the colon. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.
• Capsule endoscopy: A procedure used to see all of the small intestine. The patient swallows a capsule that contains a tiny camera. As the capsule moves through the gastrointestinal tract, the camera takes pictures and sends them to a receiver worn on the outside of the body.
• Biopsy: The removal of cells or tissues so they can be viewed under a microscope to check for signs of cancer. Tissue samples may be taken during endoscopy and colonoscopy.

Signs and Symptoms

Some gastrointestinal carcinoid tumors have no signs or symptoms in the early stages.

Signs and symptoms may be caused by the growth of the tumor and/or the hormones the tumor makes. Some tumors, especially tumors of the stomach or appendix, may not cause signs or symptoms. Carcinoid tumors are often found during tests or treatments for other conditions.

Carcinoid tumors in the small intestine (duodenum, jejunum, and ileum), colon, and rectum sometimes cause signs or symptoms as they grow or because of the hormones they make. Other conditions may cause the same signs or symptoms. Check with your doctor if you have any of the following:

Duodenum

Signs and symptoms of GI carcinoid tumors in the duodenum (first part of the small intestine, that connects to the stomach) may include the following:

• Abdominal pain.
• Constipation.
• Diarrhea.
• Change in stool color.
• Nausea.
• Vomiting.
• Jaundice (yellowing of the skin and whites of the eyes).
• Heartburn.

Jejunum and ileum

Signs and symptoms of GI carcinoid tumors in the jejunum (middle part of the small intestine) and ileum (last part of the small intestine, that connects to the colon) may include the following:

• Abdominal pain.
• Weight loss for no known reason.
• Feeling very tired.
• Feeling bloated
• Diarrhea.
• Nausea.
• Vomiting.

Colon

Signs and symptoms of GI carcinoid tumors in the colon may include the following:

• Abdominal pain.
• Weight loss for no known reason.

Rectum

• Signs and symptoms of GI carcinoid tumors in the rectum may include the following:
• Blood in the stool.
• Pain in the rectum.
• Constipation.

Carcinoid syndrome may occur if the tumor spreads to the liver or other parts of the body.

The hormones made by gastrointestinal carcinoid tumors are usually destroyed by liver enzymes in the blood. If the tumor has spread to the liver and the liver enzymes cannot destroy the extra hormones made by the tumor, high amounts of these hormones may remain in the body and cause carcinoid syndrome. This can also happen if tumor cells enter the blood. Signs and symptoms of carcinoid syndrome include the following:

• Redness or a feeling of warmth in the face and neck.
• Abdominal pain.
• Feeling bloated.
• Diarrhea.
• Wheezing or other trouble breathing.
• Fast heartbeat.

These signs and symptoms may be caused by gastrointestinal carcinoid tumors or by other conditions. Talk to your doctor if you have any of these signs or symptoms.

Treatment Options

There are different types of treatment for patients with small intestine cancer.

Different types of treatments are available for patients with small intestine cancer. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Three types of standard treatment are used:

Surgery

Surgery is the most common treatment of small intestine cancer. One of the following types of surgery may be done:

• Resection: Surgery to remove part or all of an organ that contains cancer. The resection may include the small intestine and nearby organs (if the cancer has spread). The doctor may remove the section of the small intestine that contains cancer and perform an anastomosis (joining the cut ends of the intestine together). The doctor will usually remove lymph nodes near the small intestine and examine them under a microscope to see whether they contain cancer.
• Bypass: Surgery to allow food in the small intestine to go around (bypass) a tumor that is blocking the intestine but cannot be removed.

Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given radiation therapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

New types of treatment are being tested in clinical trials.

This summary section describes treatments that are being studied in clinical trials. It may not mention every new treatment being studied. Information about clinical trials is available from the NCI website.

Biologic therapy

Biologic therapy is a treatment that uses the patient’s immune system to 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.

Radiation therapy with radiosensitizers

Radiosensitizers are drugs that make tumor cells more sensitive to radiation therapy. Combining radiation therapy with radiosensitizers may kill more tumor cells.

Patients may want to think about taking part in a clinical trial.

For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.

Many of today’s standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.

Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.

Patients can enter clinical trials before, during, or after starting their cancer treatment.

Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.

Clinical trials are taking place in many parts of the country. See the Treatment Options section that follows for links to current treatment clinical trials. These have been retrieved from NCI’s listing of clinical trials.

Follow-up tests may be needed.

Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change, or stop treatment may be based on the results of these tests.

Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.