Chemotherapy for Gastrointestinal Carcinoid Tumors
Chemotherapy (chemo) uses anti-cancer drugs that are injected into a vein or a muscle or taken by mouth to kill cancer cells. These drugs enter the bloodstream and reach all areas of the body, making this treatment useful for some types of cancers that have spread to other organs.
Unfortunately, gastrointestinal (GI) carcinoid tumors often do not respond well to chemo. Because of this, chemo generally is used only for tumors that have spread to other organs, are causing severe symptoms, and have not responded to other medicines.
Some of the chemo drugs used to treat GI carcinoid tumors include:
- Capecitabine (Xeloda®)
- 5-fluorouracil (5-FU)
- Doxorubicin (Adriamycin®)
- Etoposide (VP-16)
- Dacarbazine (DTIC)
- Cyclophosphamide (Cytoxan®)
Some tumors, especially high-grade tumors, may be treated with more than one drug. For these, combinations of etoposide plus carboplatin or temozolomide plus capecitabine may be used.
Chemo drugs kill cancer cells but also damage some normal cells, which can cause some side effects. Side effects depend on the type of drugs, the amount taken, and the length of treatment. Short-term side effects might include:
- Nausea and vomiting
- Loss of appetite
- Hair loss
- Mouth sores
- Low blood counts
Because chemo can damage the blood-making cells of the bone marrow, you may have low blood cell counts. This can result in:
- Increased risk of infection (from too few white blood cells)
- Bleeding or bruising after minor cuts or injuries (from a shortage of blood platelets)
- Fatigue or shortness of breath (from too few red blood cells)
Most side effects go away a short time after treatment. Often medicines can help prevent or minimize many of the side effects. For example, your doctor can prescribe drugs to help prevent or reduce nausea and vomiting.
Intra-arterial therapy and chemoembolization
Normally, chemo drugs enter the bloodstream and can travel throughout the body. When carcinoid cancer has spread to the liver, it is sometimes treated by directly injecting the chemo drug into the hepatic artery, which supplies blood to parts of the liver. This exposes the liver tumors to high doses of the drug but limits exposing the rest of the body. This lets patients avoid some side effects. Sometimes the chemo drug is injected together with a material that plugs up the artery (an approach called chemoembolization). When the arteries leading to them are blocked, the tumors become starved for nutrients and oxygen and many die off.
Other drugs for treating carcinoid tumors
Somatostatin analogs are man-made drugs chemically related to the natural hormone, somatostatin. These drugs can help control the symptoms caused by the hormones released from carcinoid tumors, including carcinoid syndrome. They can also help slow or stop tumor growth for a time in patients with metastatic neuroendocrine cancers.
The main somatostatin analogs used to treat carcinoid tumors are:
- Octreotide (Sandostatin®)
- Lanreotide (Somatuline® Depot)
These drugs can help treat flushing, diarrhea, and wheezing from carcinoid syndrome. They can also help slow or stop the growth of carcinoid tumors that have spread, which might help prolong life. Octreotide is also sometimes given to prevent and treat problems caused by the release of serotonin or other hormones when patients with carcinoid tumors have surgery.
The main side effects of these drugs are pain at the site of the injection and − rarely − stomach cramps, nausea, vomiting, headaches, dizziness, and fatigue. In patients that don’t have carcinoid syndrome, they can also cause diarrhea. These drugs can also cause sludging (thickening or crystallizing) of bile in the gallbladder, which can lead to gallstones. They can also raise blood sugar levels and make pre-existing diabetes more difficult to control.
Octreotide comes in a short-acting version that is given 2 to 4 times a day. It is also available as a long-acting injection (Sandostatin LAR) given only once a month, which may help patients more than the short-acting version.
Lanreotide only comes as a monthly injection.
A newer somatostatin analog, pasireotide (Signifor®), is more often used to treat the symptoms of Cushing syndrome.
Interferons are natural substances that normally activate the body's immune system. They also slow the growth of tumor cells. Interferon-alfa is sometimes helpful in shrinking or slowing the growth of metastatic neuroendocrine cancers and improving symptoms of carcinoid syndrome. Its usefulness is sometimes limited by its flu-like side effects, which may be severe. The drug is given by injection.
Cyproheptadine is an antihistamine that can help relieve some of the symptoms of carcinoid syndrome.
Other medicines are also available to control specific symptoms. Please ask your doctor about these, or describe your symptoms and ask about medicines to control them.
Last Medical Review: February 26, 2015 Last Revised: February 8, 2016