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Bowel cancer at a glance

Bowel cancer, also called colorectal cancer, is the third most common cancer in men, and the second most common cancer in women in the UK. Each year, there are about 21,617 new cases of bowel cancer in men, and nearly 13,389 cases in women.

Bowel cancer can occur anywhere in the colon or rectum (back passage). Most bowel cancers take between five and eight years to develop, and often begin as a small growth on the bowel wall called a polyp or adenoma. Sometimes bowel cancer can spread to other parts of the body, often the liver.

Click on the links below to find out more about bowel cancer.

• Risks and causes
• Signs and symptoms
• Screening
• Detection
• Treatment

Find out about what Cancer Research UK is doing about bowel cancer in the 'Our current research' section of this website.

If you are a patient looking for information on bowel cancer, please visit our patient information website, CancerHelp UK.

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Risks and causes

The most important risk factors for bowel cancer are listed below.

The risk of developing bowel cancer increases with age. Eight out of ten cases are diagnosed in people over 60.

Being overweight or obese increases the risk of bowel cancer developing.

Being inactive increases the risk of bowel cancer. Doing at least half an hour of moderate exercise five times a week can help lower the likelihood of the disease developing.

A diet that is high in red or processed meat and fat, and low in fibre, fruit, vegetables and folate can increase the risk of bowel cancer.

Smoking may increase the risk of bowel cancer, particularly in heavy drinkers. Alcohol consumption may increase risk, especially in those with low levels of folate in their diet.

If you have previously had a polyp in your bowel, especially a type called an adenomatous polyp, you are at increased risk of developing bowel cancer. You are also at increased risk if you have had bowel cancer before.

People with severe ulcerative colitis, or who have had Crohn's disease for many years, have a slightly increased risk of developing bowel cancer.

A few people are born with a much higher-than-average risk of bowel cancer because they have inherited a faulty gene from one of their parents. These people will often have a strong history of bowel cancer in their family.

There are a number of genetic conditions that are linked to bowel cancer, including familial adenomatous polyposis (FAP) and hereditary non-polyposis colon cancer (HNPCC). But overall, fewer than 1 in 20 cases of bowel cancer are due to a high-risk inherited gene defect.

You can find out more about what 'cancer risk' means in the 'Understanding 'risk'' section of this website.

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Signs and symptoms

Symptoms may include:

• blood (bright red or black flecks) or mucus in the stool (faeces)
• changes in bowel habits (diarrhoea, constipation or both) which lasts more than six weeks
• the feeling of still having to go to the toilet even after having emptied the bowels
• pain or discomfort in the stomach area (colicky pain, cramps, or tenderness)
• unexplained weight loss
• extreme tiredness (this may be due to bleeding)
• a lump in the abdomen.

These symptoms may well be due to other causes. The most common cause for bleeding, for example, is piles (haemorrhoids). However, people who notice any symptoms should see their doctor. Generally, the earlier bowel cancer is detected, the better the chance of cure.

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Screening

The NHS is currently rolling out a national bowel cancer screening programme across the UK. The programme will be based on the Faecal Occult Blood (FOB) test, which looks for blood in the faeces.

The programme will be introduced in phases amongst men and women in their sixties from April 2006, and aims to cover the entire UK population by 2009. You can find out more information on the NHS Bowel Cancer Screening webpage

Large scale pilots of a second method, flexible sigmoidoscopy (FSIG), which can detect pre-cancerous changes, is being carried out in people in their late fifties.

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Detection

The doctor will carry out an examination and ask questions about any previous medical problems. After referral, a specialist may carry out further tests. You can read more about these tests on CancerHelp UK, our patient information website: as:

• Rectal examination
• Faecal Occult Blood Test
• Sigmoidoscopy/Colonoscopy
• Barium enema

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Treatment

The three main treatments for bowel cancer are:

About four out of five patients undergo some form of surgery. It can be extremely successful. The type of surgery a person has depends on the stage and location of the cancer

Chemotherapy is sometimes used after surgery for some bowel cancers. It can improve survival and quality of life. Doctors might also use it to help ease the symptoms of advanced cancer.

This is rarely used for large bowel cancer except to relieve symptoms such as pain. Radiotherapy is frequently used to treat cancer that started in the back passage.

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