Carcinoid syndrome: can it be treated?

What are the causes?

The symptoms of carcinoid syndrome are caused by carcinoid tumours releasing hormones into the bloodstream. These tumours tend to be small and yellow and have well defined edges. They crop up along the digestive tract, being most common in the appendix, rectum and small intestine, although they can occur in the lungs in some people.

The tumours form from cells that were originally part of the neuroendocrine system – this system is responsible for producing the hormone serotonin. When they grow out of control, the tumours over produce serotonin, which is released into the body where it creates havoc with body systems. Fortunately, carcinoid syndrome occurs in only 10% of people with carcinoid tumours, usually after the tumour has spread to the liver or lung.

Symptoms

The most common symptoms of carcinoid syndrome are due to the effects of excess serotonin and include:

• Flushing of the face and neck
• Severe diarrhoea
• Intermittent abdominal pain
• Nausea and vomiting
• Heart palpitations
• Low blood pressure
• Shortness of breath/wheezing

Some people with carcinoid syndrome find that their symptoms are brought on by physical exertion, stress, or eating or drinking certain things such as blue cheeses, chocolate, or red wine. A diet high in fibre or fatty/greasy foods can make the diarrhoea associated with carcinoid syndrome worse.

Can it be treated?

The mainstay of treatment for carcinoid syndrome is to treat the underlying carcinoid tumour. The preferred treatment for carcinoid tumours in most cases is surgical removal or reduction (‘debulking’) of the tumour. Depending on the location of the tumour, however, surgery may not always be possible. If you aren’t able to have surgery, you will be offered several other options for treating your carcinoid tumours and the resulting carcinoid syndrome:

• Somatostatin analogues, such asoctreotide, sandostatin or lanreotide, act by reducing the amount of circulating hormones that cause the symptoms of carcinoid syndrome. Somatostatin analogues are given via subcutaneous injection (under the skin) three times a day, which you can learn to do yourself at home.
• Chemotherapy works by destroying the tumour cells and reducing the size of the tumour causing carcinoid syndrome. Chemotherapy is not usually a first-choice treatment for carcinoid tumours, but may be used if surgery is not possible or if the tumour is fast growing.
• Hepatic artery embolisation cuts off the blood supply to the tumour, thereby reducing the amount of hormones it can release. This treatment is generally considered when the tumour has spread to the liver, or when other treatments don’t adequately control your symptoms.
• Heat treatment/radiofrequency ablation is only used in tumours of the liver. A probe is inserted into the tumour, where a radiofrequency current is passed through the probe, producing large amounts of heat which destroys the tumour cells.

You may be offered a combination of treatments for the most effective control of carcinoid syndrome. For example, chemotherapy may be used in combination with somatostatin analogues, or before or after surgery.

Associated complications

In rare cases, carcinoid syndrome can lead to other complications such as heart disease and carcinoid crisis.

• Heart disease as a complication of carcinoid syndrome is caused by thickening of the valves around the heart as a result of the high levels of hormones in the blood. About half of people with carcinoid syndrome have cardiac abnormalities such as heart failure. If you develop heart disease, your doctor may need to perform additional tests and prescribe additional treatment to monitor and manage your condition.
• Carcinoid crisis is a rare complication of carcinoid syndrome in which symptoms such as flushing, low blood pressure and breathlessness can escalate rapidly. A carcinoid crisis can occur for no apparent reason, or may be triggered by chemotherapy or by receiving an anaesthetic. Treatment with octreotide can be used prior to surgery to prevent it.

Self-help

In addition to medical treatment, there are things you can do yourself to help manage the symptoms of carcinoid syndrome. Keeping records of when your symptoms occur can help you to work out if certain triggers, such as stress or particular foods or drinks, cause your condition to worsen. It is also important to replace the fluid and electrolytes that you lose through diarrhoea. Drinking little and often and drinking electrolyte replacement drinks can help.

You may also be able to join a support group. Your nurse or doctor will be able to tell you about support groups in your area, or you can contact a carcinoid syndrome organisation directly.