Risks and causes of carcinoid tumours

A risk factor is anything that can increase your chance of developing cancer. Different cancers have different risk factors.

Remember - Having one or more risk factors does not mean that you will definitely get carcinoid. Many people with one or more risk factors never get carcinoid. And some people with none of the risk factors do develop carcinoid. Risk factors are only a guide to what may increase your risk.

Carcinoid tumours are rare. Only 1,200 people are diagnosed each year in the UK. Carcinoid is slightly more common in men than women. It is most common in middle aged people, although anyone can develop it at any age. Unfortunately, there is very little information about what causes carcinoid, or increases your risk of developing it. Doctors think that most cases happen by chance.

Carcinoid tumours develop more often than usual in people who have a rare family syndrome called multiple endocrine neoplasia type 1 (MEN1). People with MEN1 have a higher risk than normal of carcinoid tumours and tumours of the pituitary gland, pancreas and parathyroid gland. 1 in 10 people (10%) with carcinoid tumour have MEN1. Your doctors may ask you about your family history of cancer to check if there are any other people with cancer in your family.

If a close relative (a brother or sister, mother or father) has carcinoid, it increases your risk of developing a carcinoid tumour. But it is important to remember that MEN1 is an extremely rare syndrome and fewer than 1 in 100 people (1%) diagnosed with carcinoid will have anyone else in their family who has had a carcinoid tumour. 

A large German study has shown that children of parents with carcinoid tumour have a risk of carcinoid tumour that is 4 times higher than the general population. People also have an increased risk of carcinoid tumour if they have a parent with squamous cell skin cancer or cancer of the brain, breast, liver, endocrine glands, bladder or kidney. People with a brother or sister diagnosed with colon or rectal cancer also have an increased risk of digestive system carcinoid tumours.

People who have a condition called neurofibromatosis also have a higher than normal risk of getting a carcinoid tumour of the small bowel.

Carcinoid is slightly more common in black men of African descent than it is in other ethnic groups.

Under the age of 50 years, more women than men develop carcinoid. But after 50, men are twice as likely as women to develop it.

A European study found that people who smoke have an increased risk of developing carcinoid of the small bowel and atypical lung carcinoids compared to non smokers. We need more research to confirm this.

A Swedish study has shown that people who eat a lot of saturated fat have a risk of carcinoid tumours that is 3 or 4 times higher than people who have low levels of saturated fat in their diet.

If you have had any condition that changes the production of acid in the stomach, such as a peptic ulcer or Zollinger Ellison syndrome, you have a slightly increased risk of developing

• Carcinoid of the gastrointestinal tract
• Carcinoid of the bowel
• Carcinoid of the stomach