Carcinoid Syndrome

Medically Reviewed by Jennifer Robinson, MD on June 19, 2024
5 min read

Carcinoid syndrome is a group of symptoms you might have with a type of cancer called carcinoid tumors. These tumors start in cells that make certain chemicals, and they release more of those chemicals into your bloodstream.

The symptoms can be similar to those of other conditions like menopause or asthma. For example, there may be times when your skin suddenly gets red and warm, you have trouble breathing, or you have a rapid heartbeat.

Carcinoid tumors usually grow in your stomach and intestines, but you can also get them in your lungs, pancreas, testicles, or ovaries. If you have carcinoid syndrome, it usually means the cancer has spread, most often to your lungs or liver.

If your doctor finds a tumor early, they might be able to remove it. But other times, there’s no cure for carcinoid tumors. Treatments can help you live longer and better. You can also take steps to relieve the symptoms and feel more comfortable.

Carcinoid syndrome happens because the tumors can make chemicals like hormones. When the cancer has spread to your liver, these chemicals can get into your blood. There, they can travel around your body and cause symptoms. The chemicals can go directly into your bloodstream if you have tumors in your lungs, testes, or ovaries.

People with carcinoid syndrome may have:

Carcinoid syndrome can lead to other problems, including:

  • Carcinoid heart disease. This can make your heart valves get thick and leak. Medicine can help, and in some cases, you may need surgery.
  • Bowel blockage. A tumor in the lymph nodes next to your small intestine can block your digestion. This causes severe belly pain and vomiting. You might need surgery.
  • Carcinoid crisis. Rarely, you might have a severe episode of blushing, trouble breathing, and confusion. This is an emergency that could be life-threatening, so get medical help right away.

If your doctor thinks you have carcinoid syndrome, they’ll do a physical exam and may ask you questions like:

  • Have there been times when your skin suddenly got red and felt warm or burning?
  • Do you often have diarrhea?
  • Have you been short of breath?
  • Do you sometimes wheeze?

You may also need tests to look for a carcinoid tumor.

Urine test. You collect your pee in containers over a 24-hour period. A lab will check it for high levels of hormones or what's left when your body breaks them down.

Blood test. This could also show chemicals that the tumors release.

Imaging tests. A CT scan is a series of X-rays that gives detailed views of the inside of your body. An MRI uses strong magnets and radio waves to make pictures of your organs. For radionuclide scanning, your doctor will inject you with a small amount of radioactive material, and your organs will absorb it. A special camera can spot the material and make pictures that help your doctor find a tumor.

  • Where are the tumors that are causing my carcinoid syndrome?
  • What kinds of tests will I need?
  • What treatment do you recommend?
  • Are there any foods I should avoid?
  • What can I do to control my skin flushing?
  • What other symptoms should I watch out for?

To treat carcinoid syndrome, your doctor will need to treat your tumors. You could have just one treatment or a combination of them.

Surgery. Doctors may take out an entire organ that has tumors, such as your appendix, or remove only part of an affected area, such as a section of your bowel.

Depending on where the tumor is, your doctor may also use an electric current to burn it off or cryosurgery to freeze it. Another option could be radiofrequency ablation. It uses a tool that sends electrical energy into the tumor to kill cancer cells.

Chemotherapy. Strong medicines can often kill your cancer cells or slow their growth. You can take some of these drugs by mouth and get others through injections into a vein.

Radiation. This treatment can destroy cancer cells or keep them from multiplying. The radiation can come from a machine outside your body, or your doctor may place a small amount of radioactive material inside your body, in or near the tumor.

Liver directed therapy. This treatment kills cancer cells in your liver by blocking their blood supply. Your doctor threads a tube called a catheter into one of the arteries that carries blood to your liver. Then, they inject particles that block the blood flow to liver tumors.

Biologic drugs. This type of treatment, which is also called immunotherapy, strengthens your body's defenses. Doctors inject drugs that help your immune system kill cancer cells.

Drug therapy. Injected drugs such as lanreotide (Somatuline) and octreotide (Sandostatin) can help with skin flushing. They may also have a small effect on tumor growth. Telotristat ethyl (Xermelo) along with lanreotide or octreotide can help ease diarrhea.

Lanreotide and octreotide attach to carcinoid cells and cut down on the amount of chemicals they make. Their side effects can include nausea, gallstones, and pain or bruising where you inject it.

In some cases, doctors give octreotide with a medicine called interferon alfa to boost your body's response.

You can make smaller changes to curb the effects of carcinoid syndrome. For instance, avoid certain foods and drinks that can trigger symptoms:

It might take some trial and error to learn which are triggers for you.

Your intestines could have trouble absorbing nutrients, which can lead to weight loss, weakness, and other problems. Try to eat a healthy diet, and ask your doctor whether you need to take vitamins or supplements.

Treatment might make the tumors go away. But the cancer may not be gone completely, or it could return. You may need regular therapy to keep it in check for as long as possible.

If your treatment stops working, you can focus on making sure you're as comfortable as possible. This is called palliative care.

You don't have to face things alone. Consider joining a support group where you can you share your feelings with others who understand what it's like.

Learn more about carcinoid syndrome and carcinoid tumors on the website of the Carcinoid Cancer Foundation. It also has information about how to join support groups in your area.