Colorectal cancer screening

What is bowel cancer?

The most common cancer in Australia (after skin cancer)

This cancer develops silently over years from uncontrolled, wart-like growths on the inner surface of the large bowel called polyps

Removing pre-cancerous polyps prevents bowel cancer

90 per cent of bowel cancers can be treated successfully, if detected early


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Who is at increase risk of getting bowel cancer?

  • Before 85 years, the lifetime risk in Australia is:

1 in 10 for men                1 in 15 for women

  • Risk increases with age
  • Men tend to get it 5-10 years earlier than women
Approximate risk over the next….
If a person is aged 5 years 10 years 15 years 20 years
30 1 in 7000 1 in 2000 1 in 700 1 in 350
40 1 in 1200 1 in 400 1 in 200 1 in 90
50 1 in 300 1 in 100 1 in 50 1 in 30
60 1 in 100 1 in 50 1 in 30 1 in 20
70 1 in 65 1 in 30 1 in 20 1 in 15
80 1 in 50 1 in 25

Bowel cancer risk is higher for people who have:

  • blood passed during a bowel motion
  • changes in bowel habits lasting more than two weeks
  • prior bowel cancer or polyps
  • a family member with bowel cancer or advanced polyps
  • colitis for more than 10 years

Do I need bowel cancer screening if I have no symptoms and no family history? YES

  • Just by living in Australia, we have the third highest risk of bowel cancer in the world (after Slovenia and New Zealand)
  • Bowel cancer is most common in people with no symptoms and no family history
  • It is Australia’s forgotten, most common, life-threatening but preventable cancer
  • If you wait for symptoms, it may be too late to cure
  • Earlier detection save lives and improves outcome
  • One of the easiest cancers to catch early if screened at a preventable and curable stage (at polyp stage or before symptoms)
  • There are several safe, acceptable and effective screening tests available

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What screening options do I have after I turn 50? – there is no perfect option

Option 1: Faecal Occult Blood Test every 1-2 years (FOBT stool test) +/- one lifetime colonoscopy at 60-65 years old

  • Conveniently done at home, this non-invasive, inexpensive test, detects “invisible” bleeding of  early stage “silent” bowel cancer or polyps
  • Bowel cancer or polyps may bleed silently for several years. The only way to find this silent bleeding is with a FOBT stool test.
  • On a 15 year program, it decreases your chance of dying from bowel cancer 1% per year if you check a FOBT every 2 years and 2% per year if done annually. Namely, it is proven to  decrease bowel cancer death by 15%  if repeated every 2 years or 30%  if repeated annually over 15 years respectively.
  • 1 or 2 negative FOBTs is not an “all clear”. Negative test may still have a cancer or polyps. You must stay in the program for over 10 -15 years to be worthwhile
  • positive FOBT = bowel cancer only 3-5%. All positive FOBTs need  colonoscopy to investigate cause.

 Option 2: Colonoscopy every 10 years (starting age: 40 if family history, 50 men, 55 women)

  • most accurate, well tolerated and probably the most effective
  • proven decrease bowel cancer death by at least 50%
  • needs bowel preparation, 2-4 hours in day hospital, sedation
  • most costly, 1 in 500 may have a serious complication
  • negative test does not exclude polyps or cancer in 100%.

 Option 3: Flexible sigmoidoscopy every 5 years plus FOBT

  • This is a common choice in the UK.
  • accurate, avoid large volume bowel preparation, no sedation
  • only examines left side of bowel where most bowel cancer is found and to decrease risk of missing right-sided lesions do FOBT
  • 1 in 15000 may have a serious complication

Option 4: CT- colonography every 5 years

  • accurate and easy to perform provided reporting doctor is experienced
  • may miss small polyps, needs bowel prep, may be uncomfortable
  • radiation dose = 350 Xrays
  • need colonoscopy for polyps
  • often find irrelevant lesions which bring further worry and require followup testing and scans for month/years

Is bowel screening for me?

  • If you are 50 years or over, bowel cancer screening may save your life
  • Australians are being invited to take part in a new Government funded program using the “FOBT every 2 years” option to be fully implemented in 2020
  • Over 70% of Australians have probably had some form of bowel cancer screening.
  • currently over 60% (even when offered FOBT screening) do not take it up. This is partly why we have not seen a significant decrease in bowel cancer deaths in Australia since the 1960s.
  • Many people who come to a specialist favour colonoscopy every 10 years (or every 5 years if there is a family history). There are also many who choose the less invasive, convenient FOBT stool test at home every year (or two).
  • Screening for bowel cancer, when you feel well, have no symptoms and have no family member with bowel cancer, is a preventative health decision.
  • Other examples include: asking a doctor for a‘flu shot or to check your blood pressure or sugar level for diabetes, or an annual skin check for skin cancers, or for women, a mammogram for breast cancer or pap smears for cervical cancer or, for men a prostate examination
  • Talk your decision over with your doctor. Encourage the people close to you over 50 to do the same. Each option has a set of benefits and risks. None is 100% accurate. Any form of bowel cancer screening may save your life or a loved one and is better than waiting until it is too late.

“Are you over 50?

                                             … then you are at significant risk for bowel cancer.

As Australians we are number 3 in the world rankings after Slovenia and New Zealand”

“Deaths from bowel cancer have not fallen much since the 1960s.

Don’t die from embarrassment. Screening saves lives.”