Family history of bowel cancer

Bowel cancer is very common. It often develops in a person’s 60 or 70s, but can develop much earlier in life. There are around 40,000 new cases of bowel cancer diagnosed every year in the UK. General and colorectal surgeon Mr Ian Botterill takes a look at how a family history of bowel cancer affects a person’s chances of developing the condition.

As the symptoms of bowel cancer can be very subtle and may not become obvious for a long period of time, it may be important for people worried about their family history of bowel cancer to seek medical advice to determine if they have polyps, which are regarded as a typical precursor of bowel cancer.

How much does family history influence the risk of bowel cancer?

Around one-third of newly diagnosed patients with bowel cancer will also have another family member affected with the disease. Around 10% of bowel cancer sufferers will, in fact, have a significantly increased risk by virtue of a close family member (‘first-degree relative’) also being affected, particularly if that person was less than 50 years old when they were diagnosed.

Some families may be severely affected by other cancers as well. These families may, unfortunately, have several members affected by bowel cancer or other related cancers ( breast, ovary, stomach, pancreas, for example). The most commonly recognised family history groups are termed: ‘Familial Polyposis Coli’ and Lynch syndrome. There are many other less common diagnostic groups.

What should a person do if worried about their risk of bowel cancer?

If concerned about your family history of bowel cancer, it is advisable to seek specialist advice from a colorectal surgeon. A detailed family history of affected family members will be taken at the initial out-patient consultation. Following this, and depending on the nature of the family history, plus any other bowel symptoms, it is likely that a colonoscopy will be advised.

In the hands of an experienced colonoscopist, the entire large bowel can be visualised in at least 90% of cases. During this procedure, which can be done with or without sedation, the bowel lining is assessed, and any small polyps can usually be easily removed. The timings of any possible future colonoscopies would be determined by the family history and the number, size and type of polyps that might be found.

If a particularly worrying family history is described, the next step might involve referral to a clinical geneticist. A geneticist is an expert at genetically analysing previously removed cancers (where possible) or giving more detailed advice on what further screening procedures might be needed for the individual patient and their family.

If you have a strong family history of bowel cancer in your family, don’t hesitate to contact Mr Ian Botterill for further information.