What are Gastrointestinal Carcinoid Tumors?

Gastrointestinal carcinoid tumors are an unusual, slow-growing type of cancer that most commonly appear in the lining of the gastrointestinal tract. These tumors rarely cause any signs or symptoms until late in the disease, when they become large and invade the liver. As a result, diagnosing gastrointestinal carcinoid tumors early can be challenging and are often discovered during an examination for another condition.

Under a microscope, a carcinoid tumor may appear to be benign, but may have already spread.  

Having a carcinoid tumor increases an individual’s chance of getting other gastrointestinal cancers, either at the same time or later.

What are the symptoms of Gastrointestinal Carcinoid Tumors?

As mentioned above, there are often no signs and symptoms in the early stages. If the tumor spreads to the liver or other parts of the body, which is called carcinoid syndrome, signs and symptoms may appear such as:

• Redness or a feeling of warmth in the face and neck
• Diarrhea
• Shortness of breath, fast heartbeat, tiredness, or swelling in the feet or ankles
• Wheezing
• Pain or a feeling of fullness in the abdomen
• Skin changes
• Abdominal pain
• Intestinal obstruction

What are the risk factors for Gastrointestinal Carcinoid Tumors?

Risk factors may include:

• Sex – carcinoid tumors affect women more often than men.
• Having a family history of multiple endocrine neoplasia type 1 (MEN1) syndrome
• Having atrophic gastritis, pernicious anemia or Zollinger-Ellison syndrome
• Smoking tobacco

Screening & Diagnosis for Gastrointestinal Carcinoid Tumors

Screening and diagnostic methods for carcinoid tumors include the following:

• physical exam and history
• blood tests
• 24-hour urine test

Staging & Prognosis

There are no standard stages for gastrointestinal carcinoid tumors; they are usually judged by their size and activity. In order to plan treatment, it is important to know whether the tumor can be removed by surgery. The following tests or procedures may be used:

• Endoscopy – there are two types which may be used, depending on the location of the tumor:
  • Colonoscopy -  During a colonoscopy, the doctor examines your colon with a special instrument called an endoscope. This instrument is a long flexible tube, similar to a telescope, which lets the doctor clearly see the inside of your colon.
  • Upper endoscopy - An upper endoscopy, or EGD, allows your physician to examine the upper part of your gastrointestinal tract, which includes the esophagus, stomach and duodenum (first part of the small intestine).
• CT (CAT) Scan - A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly.
• Somatostatin receptor scintigraphy (SRS)
• Octreotide scan
• Biopsy
• Angiogram, or arteriogram - An arteriogram is also called an angiogram. An arteriogram is an x-ray image of the blood vessels to evaluate various vascular conditions, such as an aneurysm (ballooning of a blood vessel), stenosis (narrowing of a blood vessel), or blockages.
• PET Scan - a computer-based imaging technique that uses radioactive substances to examine body processes. For example, a PET scan of the heart provides information about the flow of blood through the coronary arteries to the heart.
• X-rays

The prognosis (chance of recovery) depends 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

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.        

There are seven types of treatment used for gastrointestinal carcinoid tumors:

• Surgery - Treatment of gastrointestinal carcinoid tumors usually includes surgery. The type of surgery is dependent on the location of the tumor.
• Radiation therapy - the use of high-energy radiation to kill cancer cells and to shrink tumors. There are two ways to deliver radiation therapy:
  • external radiation (external beam therapy)
    External beam radiation is a treatment that precisely sends high levels of radiation directly to the cancer cells. The machine is controlled by the radiation therapist. Since radiation is used to kill cancer cells and to shrink tumors, special shields may be used to protect the tissue surrounding the treatment area. Radiation treatments are painless and usually last a few minutes.
  • internal radiation (brachytherapy, implant radiation)
    Internal radiation therapy is given inside the body as close to the cancer as possible. Substances that produce radiation, called radioisotopes, may be swallowed, injected, or implanted directly into the tumor. Some of the radioactive implants are called "seeds" or "capsules." Internal radiation involves giving a higher dose of radiation in a shorter time span than with external radiation. Some internal radiation treatments stay in the body temporarily. Other internal treatments stay in the body permanently, though the radioactive substance loses its radiation within a short period of time. In some cases, both internal and external radiation therapies are used.
• Chemotherapy - the use of anticancer drugs to treat cancerous cells. In most cases, chemotherapy works by interfering with the cancer cell's ability to grow or reproduce. Different groups of drugs work in different ways to fight cancer cells. The oncologist will recommend a treatment plan for each individual.
• Percutaneous ethanol injection - also called intratumoral ethanol injection, this is a cancer treatment in which a small needle is used to inject ethanol (alcohol) directly into the tumor to kill cancer cells.
• Biologic (or immuno) therapy -  a treatment which is used to boost the patient’s immune system using substances made by the body or in a laboratory to restore the body’s natural defenses against cancer.
• Hormone therapy - a cancer treatment which removes hormones or blocks their action and stops cancer cells from growing. 
• Other drug therapy, such as MIBG (metaiodobenzylguanidine) is sometimes used, with or without radioactive iodine, to lessen the symptoms of gastrointestinal carcinoid tumors.

Prognosis

As these tumors vary in their degree of invasiveness and malignancy, the prognosis may be from very good to fair or poor. 

Last updated 6/08 by S. Mobarhan, MD