Cancer of the bowel

What is it?

Bowel cancer (also called colorectal cancer) is the development of malignant growths in the large bowel. The large bowel is the last part of the digestive tract through which food passes before it reaches the anus.

What are the main symptoms?

A change in bowel habits, such as bouts of constipation or diarrhoea or changes in stool consistency.
Rectal bleeding, blood mixed in the stool or dark stools. It's a mistake to think that only dark blood is bad news — depending on where the cancer is, the blood can be bright red.
Abdominal pain.
Weight loss.
Poor appetite.
Anaemia (low red blood cell count).
A lump in the abdomen.
Tiredness.

However, you may also get these symptoms for many other non-life-threatening bowel conditions.

What's the risk?

Bowel cancer is the third most common form of cancer in the UK with over 35,000 new cases every year, but the second most common cause of cancer death with around 16,000 people dying annually from the disease. Some 95% of cases of bowel cancer occur in the over 50s and it's slightly more common in men than in women.

What causes it?

Bowel cancer is caused by genes in the cells lining the gut becoming defective. These cells start to multiply and form a polyp, or small protrusion. Most polyps are benign and cause no harm, but some can become cancerous.

A high-fat, low-fibre diet contributes to the development of bowel cancer; in fact, the typical Western diet is believed to account for 80% of cases.
If you have a sedentary lifestyle, or suffer from inflammatory bowel disease (such as ulcerative colitis or Crohn's disease), you run an increased risk of developing bowel cancer.
There's also a strong genetic element to the disease. Around 6% of people with bowel cancer have a family history of the disease. You will have a four-fold increased risk of developing bowel cancer if a close relative (parent, child, brother, sister) was diagnosed before the age of 45. However, if you have a close relative who was diagnosed after the age of 60, you have the same risk of developing this cancer as the rest of the population.

How can I prevent it?

A diet rich in fruit and vegetables and low in fat protects against bowel cancer. Bananas, peaches, carrots, broccoli, green peppers, oranges, spinach and spring greens are especially useful. Olive oil can also be protective.
Eat plenty of wholemeal bread, high-fibre cereals, brown rice and pasta.
Cut down on tea and coffee
Cut right back on red and processed meats, fried foods, chocolates and cakes. Trim the fat off meat and poultry.
Make sure you don't weigh too much for your height — if you do you will have a higher risk of developing cancer.
Exercise — people who have exercised throughout their lives run the lowest risk of colon cancer.
Get to know your bowel habits. Check your stools against the Bristol Scale.
Don't rely on home-testing kits. Some foods, like beetroot, can give a "false" positive.

Should I see a doctor?

If your bowel habits have changed, or if you have blood in your stool, see your doctor immediately.

A national screening programme for bowel conacer will be introduced in 2006. In the meantime, you should ask to be examined if you have any of the symptoms of bowel cancer, especially if the disease runs in your family.

The doctor may give you a rectal examination and refer you to a specialist for further tests. He or she may also ask for a stool sample to test for the presence of blood.

What are the main treatments?

Polyps can be removed surgically, and most polyps are not cancerous. If your polyp is malignant, but the cancer has not spread, then its removal is the end of the story.
However, most cancers are found in the gut wall and are treated by surgical removal, followed by a course of chemotherapy. Recent research has shown that radiotherapy before surgery also reduces the chances of the cancer returning.
It may be necessary for you to have an operation where the cut end of the colon is brought to the surface of the skin and the faeces then empty into a bag attached to the front of the abdomen. This is called a colostomy or ileostomy, depending on which part of the bowel is used. Such an operation is usually temporary.

How can I help myself?

See the malehealth.co.uk section on cancer.

What's the outlook?

If bowel cancer is caught early enough, the cure rate is 90%.

Eight out of ten people with bowel cancer have surgery, but the cancer recurs in about half of patients. This is because the cancer has spread to other organs, usually the liver. About half the people who have had surgery live for at least three years and 40% are alive at least ten years later.