The neuroendocrine system is a series of glands that produce hormones that are carried in the bloodstream. These hormones have different roles in the body.
Carcinoid is a rare tumour that begins in cells in the neuroendocrine system. About 80% of carcinoid tumours grow in the appendix and small bowel. But they can also develop in the pancreas, lungs, stomach, ovaries, kidneys or testicles. Carcinoid tumours grow at different rates but they're usually very slow growing tumours. They may not grow or cause problems for months or years. However, some are aggressive and can quickly spread to other parts of the body and cause serious problems.
How common is carcinoid?
Carcinoid is rare. About 140 people in Victoria are diagnosed with carcinoid tumours each year. These are mainly in the small and large bowel and lung.
Risks and causes of carcinoid
It's not known what causes carcinoid tumours but there are a few factors that put someone more at risk. They include:
- having a rare family syndrome called multiple endocrine neoplasia type 1 (MEN1)
- being a black African male: these men have a slightly higher risk of developing a carcinoid tumour
- age and gender: carcinoid tumours are slightly more common in men than women
- certain stomach conditions change the production of acid in the stomach and can put you at slightly more at risk, for example, having a peptic ulcer.
Symptoms of carcinoid
Many carcinoids won't cause any symptoms. If you do have symptoms they'll depend on where in the body the carcinoid is. For example, carcinoid in the stomach can cause pain and weight loss. A lung carcinoid can cause chest pain and wheezing.
Sometimes these tumours can produce hormones, which can cause a collection of symptoms known as ‘carcinoid syndrome'. This can include:
- severe diarrhoea
- loss of appetite
- weight loss
- increased heart rate
- sudden changes in your blood pressure.
Remember, carcinoid is rare and these symptoms can all be caused by other medical conditions. However, see your doctor if you have any symptom that persists for more than 2 weeks.
Diagnosing carcinoid tumours
Your doctor will examine you and refer you for tests to see if you have cancer. This can be a worrying and tiring time, especially if you need to have several tests. If the tests show you have or may have cancer, your doctor will refer you to a specialist, who will examine you and may ask you to have more tests.
You'll have blood tests to check your general health and liver function. You may also have a blood test to check for a chemical that's sometimes high in people with a carcinoid tumour. Doctors call this a ‘tumour marker'. The most common tumour marker for a carcinoid tumour is chromogranin A (CgA).
You may also have urine tests, scans, x-rays, endoscopy and possibly a biopsy. Various scans and x-rays help doctors confirm the position of the tumour and check if it's spread to other parts of the body.
Your doctor will explain the tests to you.
‘Staging' carcinoid tumours
The test results will show whether you have cancer. They'll show where the primary cancer is and whether the cancer cells have spread to other parts of your body (this is known as metastasis). This helps your doctors ‘stage' the disease so they can work out the best treatment for you.
Staging a carcinoid tumour will depend on where the cancer is. There's no recognised system of staging a carcinoid tumour of the digestive tract. So doctors generally put them into three groups:
- Localised (the cancer hasn't spread outside its original place)
- Regional (the cancer has spread into surrounding tissue)
- Metastatic (the cancer has spread to other parts of the body)
Treatment for carcinoid tumours
If you have a slow-growing carcinoid tumour and it's not causing any problems you probably won't have treatment at first. Your doctor will keep a close eye on you and, if you develop symptoms, may decide to treat the tumour.
If you have a carcinoid that's growing and causing symptoms there are several types of treatment your doctor may suggest. They include:
- biological therapy (interferon)
- other drugs known as somatostain analogues to help control the symptoms
- hepatic artery embolisation
- radiofrequency ablation.
The type of treatment you have will depend on where the carcinoid tumour is. For more details about treatments and when they may be given, see:
Research into carcinoid tumours
Research into earlier detection and better treatments for carcinoid tumours is ongoing. However, because it's such a rare type of cancer there are fewer people to take part in clinical trials. The type of research under investigation in trials include:
- chemotherapy for carcinoid
- biological therapies added to chemotherapy to make it work better
- somatostatin analogues (drugs used to help reduce the symptoms of carcinoid tumours such as octreotide)
- genetic causes of carcinoid
- tests to help find and monitor certain carcinoid tumours better.
Cancer Council Victoria supports participation in clinical trials. Clinical trials can test the effectiveness of promising new treatments or new ways of combining cancer treatments.
Always discuss treatment options with your doctor.
Recovery and follow-up care
Your doctors may want to examine you every 3 months for the first year after your treatment, every 6 months between the second and fifth years of your treatment, and once a year after that. They'll examine you and ask about any symptoms you've had, and will answer any questions you have. Your doctor may order other tests or scans if needed.
After treatment for a carcinoid tumour you're likely to face several changes in your life. Some people may have short-term changes. Others may have permanent changes that are difficult to cope with. Most people find they need information and support about how to best deal with their situations. For more details see the links below or contact Cancer Council on 13 11 20 to speak with a cancer nurse.
For further information about neuroendocrine tumours, visit the Unicorn Foundation's website www.unicornfoundation.org.au
Expert content reviewers:
Annie Angle, cancer nurse, Dip. Oncology Nursing, Royal Marsden, London