What is the definition of Carcinoid Syndrome?

Carcinoid syndrome is a group of symptoms associated with carcinoid tumors. These are tumors of the small intestine, colon, appendix, and bronchial tubes in the lungs.

What are the alternative names for Carcinoid Syndrome?

Flush syndrome; Argentaffinoma syndrome

What are the causes for Carcinoid Syndrome?

Carcinoid syndrome is the pattern of symptoms sometimes seen in people with carcinoid tumors. These tumors are rare, and often slow growing. Most carcinoid tumors are found in the gastrointestinal tract and lungs.

Carcinoid syndrome occurs in very few people with carcinoid tumors, after the tumor has spread to the liver or lung.

These tumors release too much of the hormone serotonin, as well as several other chemicals. The hormones cause the blood vessels to open (dilate). This causes carcinoid syndrome.

What are the symptoms for Carcinoid Syndrome?

The carcinoid syndrome is made up of four main symptoms including:

• Flushing (face, neck, or upper chest), such as widened blood vessels seen on the skin (telangiectasias)
• Difficulty breathing, such as wheezing
• Diarrhea
• Heart problems, such as leaking heart valves, slow heartbeat, low or high blood pressure

Symptoms are sometimes brought on by physical exertion, or eating or drinking things such as blue cheese, chocolate, or red wine.

What are the current treatments for Carcinoid Syndrome?

Surgery to remove the tumor is usually the first treatment. It can permanently cure the condition if the tumor is completely removed.

If the tumor has spread to the liver, treatment involves either of the following:

• Removing areas of liver that have tumor cells
• Sending (infusing) medicine directly into the liver to destroy the tumors

When the entire tumor can't be removed, removing large portions of the tumor ("debulking") can help relieve the symptoms.

Octreotide (Sandostatin) or lanreotide (Somatuline) injections are given to people with advanced carcinoid tumors that can't be removed with surgery.

People with carcinoid syndrome should avoid alcohol, large meals, and foods high in tyramine (aged cheeses, avocado, many processed foods), because they may trigger symptoms.

Some common medicines, like selective serotonin reuptake inhibitors (SSRIs), such as paroxetine (Paxil) and fluoxetine (Prozac), may make symptoms worse by increasing levels of serotonin. However, DO NOT stop taking these medicines unless your provider tells you to do so.

What are the support groups for Carcinoid Syndrome?

Learn more about carcinoid syndrome and get support from:

• The Carcinoid Cancer Foundation -- www.carcinoid.org/resources/support-groups/directory/
• Neuroendocrine Tumor Research Foundation -- netrf.org/for-patients/

What is the outlook (prognosis) for Carcinoid Syndrome?

The outlook in people with carcinoid syndrome is sometimes different from the outlook in people who have carcinoid tumors without the syndrome.

Prognosis also depends on the site of tumor. In people with the syndrome, the tumor has usually spread to the liver. This lowers the survival rate. People with carcinoid syndrome are also more likely to have a separate cancer (second primary tumor) at the same time. Overall, the prognosis is usually excellent.

What are the possible complications for Carcinoid Syndrome?

Complications of carcinoid syndrome may include:

• Increased risk of falls and injury (from low blood pressure)
• Bowel obstruction (from tumor)
• Gastrointestinal bleeding
• Heart valve failure

A fatal form of carcinoid syndrome, carcinoid crisis, may occur as a side effect of surgery, anesthesia or chemotherapy.

When should I contact a medical professional for Carcinoid Syndrome?

Contact your provider for an appointment if you have symptoms of carcinoid syndrome.

How do I prevent Carcinoid Syndrome?

Treating the tumor reduces the risk of carcinoid syndrome.

REFERENCES

National Cancer Institute website. Gastrointestinal carcinoid tumors treatment (Adult) (PDQ) - health professional version. www.cancer.gov/types/gi-carcinoid-tumors/hp/gi-carcinoid-treatment-pdq. Updated September 16, 2020. Accessed October 14, 2020.

Öberg K. Neuroendocrine tumors and related disorders. In: Melmed S, Auchus, RJ, Goldfine AB, Koenig RJ, Rosen CJ , eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 45.

Wolin EM, Jensen RT. Neuroendocrine tumors. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 219.