Australia is in the unenviable position of having thehighest rates of bowel cancer in people under 50 in the world.
The perception it is an “older person’s disease” is being overturned. Rates in those over 50 have declined in Australia, while early-onset cases in people under 50 are rising by up to 8% a year.
It is thedeadliest cancer for Australians aged 25 to 44, and the risk of being diagnosed in Australia under the age of 40 hasmore than doubled since 2000.
Experts say they still do not know what has prompted Australians born in the 1990s to be diagnosed at three times the rate of those born in the 1950s.
Nevertheless, they say it’s important to raise awareness of thesigns and symptoms among young people which are often easily dismissed.
The most common signs and symptoms of early-onset bowel cancer are blood in the stool, abdominal pain, a change in bowel habits and unexplained weight loss.
Bowel Cancer Australia says people should not delay talking to their GP if they are experiencing any of these symptoms for two weeks or more – when diagnosed early, almost 99% of cases can be successfully treated. Although many of the symptoms are common to multiple health concerns, Bowel Cancer Australia urges people not to accept “you’re too young to have bowel cancer” as an explanation for symptoms, and to ask for further investigations.
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A colorectal surgeon and Bowel Cancer Australia’s medical director, Associate Prof Graham Newstead, says some people experience no symptoms. The most obvious symptoms tend to emerge as the growth in the bowel from polyp to cancer becomes large enough to partially block the bowel. Thisresults in a change in bowel habit “that’s more than the dinner you ate last night upsetting you”.
There are key barriers to early detection – a lack of symptom awareness and stigma among them. Bowel Cancer Australia’s chief executive, Julien Wiggins, says the organisation has tried to overcome people’s “taboo around checking their poo”by partnering with Kleenex to create a roll that reminds them to do so.
Screening is able to detect small amounts of blood in the stool which has leaked from growths in the bowel – even if you can’t see it yourself.
The government’s national screening program sends at-home test kits to in the mail to every Australian every two years starting from age 50. That runs up until age 74. Since July 2024, 45- to 49-year-olds can opt in to request the test for free, and then will start receiving it every two years.
People aged 40 to 44 can go to their GP and request a test. For people under 40, tests have to be bought out of pocket but Bowel Cancer Australia is advocating for lowering the screening age in response to the increasing rates of bowel cancer in younger people.
If a test comes back positive, or people notice any other symptoms such as a lump or swelling in the abdomen or extreme tiredness for no reason, they should follow up with a GP who can refer them to get a colonoscopy.
Age, family history, hereditary conditions and personal health history can all influence bowel cancer risk – they’re known as“non-modifiable” risk factorsbecause they cannot be changed.
There are alsomodifiable risk factorswhich can be controlled, including diet and lifestyle choices, as well as screening and surveillance.
Alcohol, smoking, eating too much red meat or processed meats and having increased body fat are known to increase risk.
One study of more than 540,000 women has foundthat each 20g of alcohol a day – about the amount found in a large glass of wine – was linked to a 15% higher risk of bowel cancer, while each 30g of red and processed meat a day was linked to an 8% increase in risk of the disease.
That same study found each daily 300mg of calcium, about the amount found in half a pint of milk, was associated with a 17% lower risk of bowel cancer – the same decrease Bowel Cancer Australia says is associated with eating at least 90g of wholegrains a day, such as brown rice or wholemeal bread. Recreational physical activity can reduce risk of colon (not rectal) cancer by 16%.
Bowel Cancer Australia recommends including dairy products such as low-fat milk, yoghurt and cheese in your daily diet, or considering calcium supplements if you are lactose-intolerant, as well as filling two-thirds or more of your plate with wholegrains, vegetables, fruits, beans and nuts to get more dietary fibre.