Chemotherapy

Chemotherapy 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, neuroendocrine tumors/cancers often do not respond to chemotherapy. Because of this, chemotherapy is generally used only for neuroendocrine tumors/cancers tumors that have spread to other organs, are causing severe symptoms, and have not responded to other medicines. Some of the chemotherapy drugs used include 5-fluorouracil (5-FU), doxorubicin, etoposide, dacarbazine, streptozocin, cisplatin, and cyclophosphamide. The tumors may be treated with more than one drug, although it's not clear that this is any more effective than using a single drug.

Chemotherapy drugs kill cancer cells but also damage some normal cells, which can cause side effects. These depend on the type of drugs, amount taken, and length of treatment. Short-term side effects might include nausea and vomiting, loss of appetite, hair loss, and mouth sores. Because chemotherapy can damage the blood-making cells of the bone marrow, you may have low blood cell counts. This can result in an increased risk of infection (due to a shortage of white blood cells), bleeding or bruising after minor cuts or injuries (due to a shortage of blood platelets), and fatigue or shortness of breath (due to low red blood cell counts).

Most side effects go away within a short time after treatment. There are also medicines that can help prevent or minimize some side effects. For example, your doctor can prescribe drugs to help prevent or reduce nausea and vomiting.

Intra-arterial Therapy and Chemoembolization

When the neuroendocrine cancer has spread to the liver, it is sometimes treated by directly injecting the chemotherapy drug into the hepatic artery, which supplies blood to parts of the liver. This exposes the liver tumors to high doses of the drug and limits exposure of the rest of the body. This can avoid many of the side effects described above. Sometimes the chemotherapy 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.

For more information on chemotherapy, see the American Cancer Society document, Understanding Chemotherapy: A Guide for Patients and Families.

Other Drugs for Treating Carcinoid Tumors

Several medicines can help control the symptoms of carcinoid syndrome in patients with metastatic neuroendocrine cancers.

Octreotide is an agent chemically related to a natural hormone, somatostatin. It is very helpful in treating the flushing, diarrhea, and wheezing from carcinoid syndrome. While this drug rarely shrinks carcinoid tumors, it may slow or stop their growth. Although this is not curative, it can prolong life. The main side effects are pain at the site of the injection, and rarely, stomach cramps, nausea, vomiting, headaches, dizziness, and fatigue. Octreotide causes sludging of bile and may cause gallstones in the gallbladder (cholelithiasis). It can also result in insulin resistance that can make pre-existing diabetes more difficult to control.

This drug has become available as a long-acting injection that needs to be given only once a month, which may help patients more than the short-acting version. A similar drug, lanreotide, is also being studied, as is a newer agent called pasireotide.

 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.

An antihistamine called cyproheptadine can help relieve some symptoms. Other medicines are also available to control specific symptoms. Please ask your doctor about these, or describe your symptoms to your doctor and ask about medicines to control them.