Overview

Cancer is a common condition. It will affect half (50%) of the population at some point. As we get older we are more likely to develop cancer as our bodies become less effective at protecting us. 

Lynch syndrome is an inherited condition that causes an increased risk of bowel cancer. It also increases the risk of developing womb (endometrial) and ovarian cancer. 

Although less common, Lynch syndrome can also cause other cancers such as: 

• small bowel 
• stomach 
• pancreas 
• skin 
• brain 
• kidney 
• bladder

People with Lynch syndrome are more likely to develop cancer at younger ages and may get cancer more than once. 

In the UK:

• around 1 in 18 women and 1 in 15 men will develop bowel cancer
• 1 in 50 women will develop ovarian cancer,
• womb (endometrial) cancer affects 1 in 36 females

About 10 to 15 out of 100 (10 to 15%) cases of bowel cancer happen when someone has inherited an increased risk of developing cancer.

About 2 out of 100 (2%) of these cancers are caused by a genetic condition called Lynch syndrome.

Genes

Genes are coded messages that give instructions for how cells in the body grow and function. Genes come in pairs and we inherit one copy from each parent.

The genes related to Lynch syndrome usually protect us from cancer by controlling the growth of cells.

If someone inherits a mutation (fault) in one copy of a Lynch-related gene, they will be more likely to develop Lynch-related cancers. They are also more like to get non-cancerous growths (such as bowel polyps and skin changes).

One of a number of genes can be faulty in Lynch syndrome. The most common genes are:

• MLH1
• MSH2
• MSH6
• PMS2 

If someone has a mutation in one of their copies of a Lynch syndrome related gene, they have a 1 in 2 (50%) chance of passing on this mutation to each child they have, regardless of their gender or the child’s gender.

Testing

We can carry out tests to investigate whether Lynch syndrome runs in your family.

You can read more about further genetic testing and predictive testing for Lynch syndrome.

In some families no genetic testing is possible. For these families screening for bowel cancer can still be arranged, and we can discuss options for reducing the risk of womb and ovarian cancer.

Deciding whether to be tested

Deciding to have genetic testing is a personal decision and can be a difficult and complex process.

Not everyone will choose to have genetic testing. If you decide against it you may still be eligible to have regular bowel screening and we will discuss this with you. 

Research studies

Regardless of the result of your testing, there may be an opportunity for you to take part in research. Your genetics clinician or a research nurse will discuss this with you. For further information, contact a member of the research team on 020 7188 2603.