What is bowel cancer?
Cancer of the large bowel is also called bowel cancer or colorectal cancer.
It is the third most commonly diagnosed cancer in the UK, with over 40,000 people diagnosed every year in the UK – over 100 every day. It is the third most common cancer in men after prostate and lung cancer, and the third most common cancer in women after lung cancer and breast cancer.
Over 80 per cent of bowel cancer cases occur in people over the age of 60.
Lifestyle factors such as diet and exercise are thought to affect the risk of developing bowel cancer.
Cancer can sometimes occur in the small bowel, but this is much less common than cancer of the large bowel.
What is meant by 'screening'?
There are two main ways of screening for bowel cancer - testing for blood in the stool (faeces or poo) and examining the inside of the bowel itself.
In its simplest form, 'screening' means looking for the early signs of a disease in healthy people who do not yet have any symptoms.
Bowel cancer screening is aimed at detecting bowel cancer at an early stage when treatment is more likely to work and long-term survival is likely to be greater.
Bowel cancer screening is carried out using kits that people can use at home to put a stool sample into.
Regular bowel cancer screening has been shown to reduce the risk of dying from bowel cancer by 15 per cent.
Stool testing is also called faecal occult blood testing (FOB). It looks for hidden (occult) blood in your stool.
If you fall within the age range of the bowel cancer screening programme in your part of the UK, you will receive a testing kit through the post every 2 years.
This allows you to collect a small sample of your bowel motions at home, wipe it onto a special card and send this card in a hygienically sealed, prepaid envelope to a laboratory for testing.
There are detailed instructions with each kit and the results will be sent to you by post within 2 weeks.
Only around 2 per cent of people tested have blood in their stool sample (an abnormal result).
In England, around 20 in every 1000 people tested will have an abnormal result and may be asked to do the test again.
Around 16 of those people will have a colonoscopy (an examination of the bowel using a flexible telescope). Of those 16, eight will have nothing abnormal found at colonoscopy, six will have polyps of the bowel wall and two will have cancer.
The bowel cancer screening programmes in the UK differ according to which region you are from.
England. Men and women aged between 60 and 75 years old are sent a stool testing kit (faecal occult blood test) every 2 years. The programme now aims to invite people aged 55 for bowel scope screening.
Bowel scope screening is also known as flexible sigmoidoscopy. This type of screening checks the inside of the lower bowel and rectum for small growths called polyps. If left untreated, polyps could lead to bowel cancer.
Northern Ireland. Here, men and women aged between 60 and 71 years old are invited for bowel screening using stool testing kits.
From 2014, this programme will be extended to people aged up to 74 years old.
Scotland. The Scottish screening programme screens men and women aged between 50 and 74 years old.
Wales. In Wales the screening programme sends testing kits to people aged between 60 and 74. People aged 50 years or over may start to be screened within the next 2 to 3 years.
If you have a positive FOB test you will be offered a colonoscopy. This is when the inside of your bowel is examined with a long flexible tube.
Some people are also offered regular screening earlier than than they would be in the national bowel screening programme if they are thought to be at higher than average risk of bowel cancer.
Conditions that increase the risk of bowel cancer include:
- Familial adenomatous polyposis (FAP). This rare disease runs in families and causes lots of polyps to grow in the bowel. Thereis a high risk that one of these polyps will become cancerous.
- Hereditary non polyposis colorectal cancer (HNPCC). This is an inherited gene fault (mutation) that increases bowel cancer risk. People with HNPCC will not have as many polyps as those with FAP do.
- A strong family history of bowel cancer.
- Ulcerative colitis or Crohn's disease – there is an increased risk of bowel cancer if you have either of these.
If you are not at a higher than average risk of bowel cancer and outside the age range covered by the UK bowel screening programmes, you are not currently eligible for bowel cancer screening on the NHS.
Other people also read:
Bowel cancer: About 6 per cent of the population in Western countries develop bowel cancer at some time during their lives.
Colon polyp removal: A polyp is an overgrowth of the lining of the bowel wall.
Colonoscopy: Colonoscopy enables the doctor to examine the lining of the bowel all the way through the colon.