General Information About Gastrointestinal Carcinoid Tumors



Gastrointestinal carcinoid tumors grow slowly. Most of them occur in the appendix (an organ attached to the large intestine), small intestine, and rectum. It is common for more than one tumor to develop in the small intestine. Having a carcinoid tumor increases a person's chance of getting other cancers in the digestive system, either at the same time or later.

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

The gastrointestinal tract includes the stomach, small intestine, and large intestine. These organs are part of the digestive system, which processes nutrients (vitamins, minerals, carbohydrates, fats, proteins, and water) in foods that are eaten and helps pass waste material out of the body. Gastrointestinal carcinoid tumors develop from a certain type of hormone-making cell in the lining of the gastrointestinal tract. These cells produce hormones that help regulate digestive juices and the muscles used in moving food through the stomach and intestines. A gastrointestinal carcinoid tumor may also produce hormones. Carcinoid tumors that start in the rectum (the last several inches of the large intestine) usually do not produce hormones.

Health history can affect the risk of developing gastrointestinal carcinoid tumors.

Risk factors include the following:

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

A gastrointestinal carcinoid tumor often has no signs in its early stages. Carcinoid syndrome may occur if the tumor spreads to the liver or other parts of the body.

The hormones produced by gastrointestinal carcinoid tumors are usually destroyed by blood and liver enzymes. If the tumor has spread to the liver, however, high amounts of these hormones may remain in the body and cause the following group of symptoms, called carcinoid syndrome:

  • Redness or a feeling of warmth in the face and neck.
  • Diarrhea.
  • Shortness of breath, fast heartbeat, tiredness, or swelling of the feet and ankles.
  • Wheezing.
  • Pain or a feeling of fullness in the abdomen.

These symptoms and others may be caused by gastrointestinal carcinoid tumors or by other conditions. A doctor should be consulted if any of these symptoms occur.

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:

  • Complete blood count: A procedure in which a sample of blood is drawn and checked for the following:
    • The number of red blood cells, white blood cells, and platelets.
    • The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
    • The portion of the sample made up of red blood cells.
  • 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 in the organ or tissue that produces it. 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.
  • Twenty-four-hour urine test: A test in which a urine sample is checked to measure the amounts of certain substances, such as hormones. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that produces it. The urine sample is checked to see if it contains a hormone produced by carcinoid tumors. This test is used to help diagnose carcinoid syndrome.

Certain factors affect prognosis (chance of recovery) and treatment options.

The prognosis (chance of recovery) and treatment options depend on the following:

  • Whether the cancer can be completely removed by surgery.
  • Whether the cancer has spread from the stomach and intestines to other parts of the body, such as the liver or lymph nodes.
  • The size of the tumor.
  • Where the tumor is in the gastrointestinal tract.
  • Whether the cancer is newly diagnosed or has recurred.

Treatment options also depend on whether the cancer is causing symptoms. Most gastrointestinal carcinoid tumors are slow-growing and can be treated and often cured. Even when not cured, many patients may live for a long time.

Stages of Gastrointestinal Carcinoid Tumors



After a gastrointestinal carcinoid tumor has been diagnosed, tests are done to find out if cancer cells have spread within the stomach and intestines or to other parts of the body.

Staging is the process used to find out how far the cancer has spread. The information gathered from the staging process determines the stage of the disease. There are no standard stages for gastrointestinal carcinoid tumors. In order to plan treatment, it is important to know the extent of the disease and whether the tumor can be removed by surgery. The following tests and procedures may be used:

  • Gastrointestinal endoscopy: A procedure to look inside the gastrointestinal tract for abnormal areas or cancer. An endoscope (a thin, lighted tube) is inserted through the mouth and esophagus into the stomach and first part of the small intestine. Also, a colonoscope (a thin, lighted tube) is inserted through the rectum into the colon (large intestine); this is called a colonoscopy.
  • 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.
  • Somatostatin receptor scintigraphy (SRS): A type of radionuclide scan used to find carcinoid tumors. In SRS, radioactive octreotide, a drug similar to somatostatin, is injected into a vein and travels through the bloodstream. 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 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.
  • Angiogram: A procedure to look at blood vessels and the flow of blood. A contrast dye is injected into the blood vessel. As the contrast dye moves through the blood vessel, x-rays are taken to see if there are any blockages.
  • PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radionuclide 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.
  • X-ray of the abdomen: An x-ray of the organs and tissues inside the abdomen. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.

Gastrointestinal carcinoid tumors are grouped for treatment based on where they are in the body.

Localized

Cancer is found in the appendix, colon, rectum, small intestine, and/or stomach only.

Regional

Cancer has spread from the appendix, colon, rectum, stomach, and/or small intestine to nearby tissues or lymph nodes.

Metastatic

Cancer has spread to other parts of the body.

Recurrent Gastrointestinal Carcinoid Tumors

A recurrent gastrointestinal carcinoid tumor is a tumor that has recurred (come back) after it has been treated. The tumor may come back in the stomach or intestines or in other parts of the body.

Treatment Option Overview



There are different types of treatment for patients with gastrointestinal carcinoid tumors.

Different types of treatment are available for patients with gastrointestinal carcinoid tumors. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. 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.

Clinical trials are taking place in many parts of the country.  Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.

Seven types of standard treatment are used:

Surgery

Treatment of gastrointestinal carcinoid tumors usually includes surgery. One of the following surgical procedures may be used:

  • Appendectomy: Removal of the appendix.

  • Fulguration: Use of an electric current to burn away the tumor using a special tool.

  • Cryosurgery: A treatment that uses an instrument to freeze and destroy abnormal tissue, such as carcinoma in situ. This type of treatment is also called cryotherapy. The doctor may use ultrasound to guide the instrument.

  • Resection: Surgery to remove part or all of the organ that contains cancer. Resection of the tumor and a small amount of normal tissue around it is called a local excision.

  • Bowel resection and anastomosis: Removal of the bowel tumor and a small section of healthy bowel on each side. The healthy parts of the bowel are then sewn together (anastomosis). Lymph nodes are removed and checked by a pathologist to see if they contain cancer.

  • Radiofrequency ablation: The use of 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.

  • Hepatic resection: Surgery to remove part or all of the liver.

  • Hepatic artery ligation or embolization: A procedure to 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.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. 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 the cells 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 spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy).

Chemoembolization of the hepatic artery is a type of regional chemotherapy that may be used to treat a gastrointestinal carcinoid tumor that has spread to the liver. The anticancer drug is injected into the hepatic artery through a catheter (thin tube). The drug is mixed with a substance that embolizes (blocks) the artery, cutting off blood flow to the tumor. Most of the anticancer drug is trapped near the tumor and only a small amount of the drug reaches other parts of the body. The blockage may be temporary or permanent, depending on the substance used to block the artery. The tumor is prevented from getting the oxygen and nutrients it needs to grow. The liver continues to receive blood from the hepatic portal vein, which carries blood from the stomach and intestine.

The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Percutaneous ethanol injection

Percutaneous ethanol injection is a cancer treatment in which a small needle is used to inject ethanol (alcohol) directly into a tumor to kill cancer cells. This procedure is also called intratumoral ethanol injection.

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.

Hormone therapy

Hormone therapy is a cancer treatment that removes hormones or blocks their action and stops cancer cells from growing. 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. 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.

Other drug therapy

MIBG (metaiodobenzylguanidine) is sometimes used, with or without radioactive iodine (I131), to lessen the symptoms of gastrointestinal carcinoid tumors.

Other types of treatment are being tested in clinical trials.

Treatments being studied in clinical trials for gastrointestinal carcinoid tumors include new combinations of chemotherapy.

Treatment Options for Gastrointestinal Carcinoid Tumors

Localized Gastrointestinal Carcinoid Tumors
Regional Gastrointestinal Carcinoid Tumors
Metastatic Gastrointestinal Carcinoid Tumors
Recurrent Gastrointestinal Carcinoid Tumors



Localized Gastrointestinal Carcinoid Tumors

Carcinoid tumors in the appendix

Treatment of localized gastrointestinal carcinoid tumors in the appendix may include the following:

  • Appendectomy.
  • Appendectomy and local excision.
  • Appendectomy, bowel resection with anastomosis, and removal of lymph nodes.

Rectal carcinoid tumors

Treatment of localized gastrointestinal carcinoid tumors in the rectum may include the following:

  • Fulguration.
  • Local excision.
  • Resection.

Surgery that saves the sphincter muscles (the muscles that open and close the anus) may be possible.

Small bowel carcinoid tumors

Treatment of localized gastrointestinal carcinoid tumors in the small intestine may include the following:

  • Local excision.
  • Resection with removal of nearby lymph nodes.

Gastric, colon, and pancreatic carcinoid tumors

Treatment of localized gastrointestinal carcinoid tumors in the stomach, colon, or pancreas is usually resection.

Regional Gastrointestinal Carcinoid Tumors

Treatment is usually surgery to remove all the cancer that can be seen at the site of the original tumor, as well as nearby tissues and lymph nodes.

If the tumor cannot be completely removed by surgery, treatment is usually palliative therapy to relieve symptoms and improve the patient's quality of life. This may include the following:

  • Resection, cryosurgery, or radiofrequency ablation to remove as much of the tumor as possible.
  • Chemoembolization to shrink tumors in the liver.

Metastatic Gastrointestinal Carcinoid Tumors

Distant metastases

If the metastatic gastrointestinal carcinoid tumor is not causing symptoms, there may be a period of watchful waiting before treatment is given. Treatment of distant metastases of gastrointestinal carcinoid tumors is usually palliative therapy that may include the following:

  • Surgery to bypass or remove part of a tumor blocking the small intestine.
  • Chemotherapy, which may include chemoembolization.
  • Radiation therapy, sometimes with radioisotopes such as radioactive iodine (I131).
  • MIBG (metaiodobenzylguanidine) therapy.
  • Biologic therapy and/or hormone therapy.
  • Clinical trials of new treatments.

Carcinoid syndrome

Treatment of metastatic gastrointestinal carcinoid tumors that are causing carcinoid syndrome may include the following:

  • Resection, cryosurgery, radiofrequency ablation, or percutaneous ethanol injection for tumors in the liver.
  • Hepatic artery ligation or embolization, with or without regional or systemic chemotherapy.
  • Hormone therapy.
  • Biologic therapy with or without chemotherapy.
  • Clinical trials of new combinations of chemotherapy.

A heart valve replacement may be done for some patients with carcinoid syndrome.

This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied.

Recurrent Gastrointestinal Carcinoid Tumors

Treatment of recurrent gastrointestinal carcinoid tumors may include the following:

  • Surgery to remove part or all of the tumor.
  • A clinical trial.

Source:  National Cancer Institute