Increasing incidence of bowel cancer in younger Australians

While it was once thought of as an older person’s disease, bowel cancer rates are increasingly on the rise amongst younger Australians, with a 266% increase in diagnoses over the past 30 years in those aged 15-24 years.

In this month’s blog, we take a closer look at bowel cancer and the increasing incidence of the disease in younger Australians, as well as the risks, symptoms and ways to help prevent against the disease.

What is Bowel Cancer?

Bowel cancer, also known as colorectal cancer, is the third most common type of cancer in Australia, claiming the lives of over 100 people every week. Australia has one of the highest rates of bowel cancer in the world and 1 in 15 Australians will develop the disease in their lifetime.

It develops when cells in the bowel lining grow too quickly, forming a clump known as a polyp or adenoma. While most polyps are usually benign, or non-cancerous, most bowel cancers form from these tiny growths, which can continue to grow for several years before changing and becoming cancerous. If left untreated, the cancer can spread to other areas of the body.

Depending on where the cancer begins, bowel cancer may be referred to as colon or rectal cancer. Around 30% of those who develop bowel cancer have a hereditary contribution, family history of the disease, or both.

The good news, however, is that bowel cancer is one of the most treatable types of cancer. If detected early, almost 99% of bowel cancers can be treated successfully.

What are the symptoms?

During the early stages of the disease, there
can often be no signs or symptoms present. Because of this, the Australian Government introduced the National Bowel Cancer Screening Program in 2006, to help reduce illness and death from the disease through early detection.

During later stages of the disease, the following symptoms can be indicators of bowel cancer:

  • Blood in the stool or rectal bleeding.
  • A recent, persistent change in bowel habit (for example, diarrhoea or constipation).
  • A change in the shape or appearance of bowel movements (for example, more narrow than usual).
  • Abdominal pain or swelling.
  • Pain or lump in the anus or rectum.
  • Unexplained tiredness or rapid weight loss (signs of anaemia).
  • Feeling that the bowel has not emptied completely after a bowel movement.

If you experience any of these symptoms for more than two weeks, it is recommended that you visit your General Practitioner (GP) for further investigation.

Risk Factors

Bowel cancer affects both men and women of all ages. The risk factors for bowel cancer can be broken down into two main categories – those that can be changed (modifiable) and those that can’t (non-modifiable).

Non-modifiable risk factors include:

  • Being aged 50 and over.
  • Having an existing inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis.
  • Having previous non-cancerous tumours in the bowel.
  • Having a strong family history of bowel cancer or polyps.

While these risk factors cannot be changed, it’s important to tell your GP if these risk factors apply to you and you have any concerns about developing the disease.

Modifiable risk factors include:

  • Being overweight.
  • Being physically inactive.
  • Having a poor diet – one which is high in red and processed meats, fried food and alcohol but low in fruits, vegetable and whole grains.

These risk factors can all be addressed through changes to your diet and lifestyle. Your GP can assist you with any health concerns you have regarding your diet and overall health and wellbeing.

In those younger than 50 years old, the risk of developing bowel cancer increases if one or more of the following symptoms have been experienced for three months to two years prior to diagnosis:

  • Abdominal pain
  • Rectal bleeding
  • Diarrhoea
  • Iron deficiency anaemia

Why are more young people being diagnosed with the disease?

According to Bowel Cancer Australia, those born from 1990 onwards are twice as likely to be diagnosed with colon cancer and four times as likely to be diagnosed with rectal cancer as those born in 1950.

The Royal Australian College of General Practitioners (RACGP) notes that the statistics show a 266% increase in bowel cancer rates amongst adolescents and young adults, aged between 15 and 24 years.

While there is yet no clear explanation for this increase, it is thought that a greater prevalence of metabolic disorders, unhealthy diet, sedentary lifestyle and obesity are all contributing to the rise in bowel cancer in younger Australians.

How can I reduce my risk of developing bowel cancer?

There are a number of ways to help reduce your risk of developing bowel cancer.

1. Take the test
Australia’s National Bowel Screening Program invites eligible people between 50-74 years of age to regularly screen for bowel cancer using a free simple test at home.

The test is able to detect blood that is difficult to detect with the naked eye; one of the possible symptoms of bowel cancer. While a positive result means blood has been detected in the sample, it does not mean that bowel cancer is present. It does, however, require further investigation by your GP.

A negative result means no blood has been detected in the samples, and no further action will be required. However, it’s important to remember that a negative test result is no guarantee that a person will not develop bowel cancer. As such, those aged between 50-74 are encouraged to take the test every two years. You should also talk to your GP immediately if you develop symptoms after getting a negative result.

With the increasing incidence of bowel cancer amongst younger age groups, there are calls for this test to be made available to Australians from the age of 45 years, as was introduced in America in 2021.

In the meantime, for those outside the 50-74 year age bracket for screenings through the National Bowel Cancer Screening Program, a BowelScreen Australia screening test can be purchased from participating pharmacies or through Bowel Cancer Australia by contacting their Helpline on 1800 555 494.

2. Adopt a healthy diet and lifestyle

There are a number of things that are in your control and can be changed to help in the prevention against bowel cancer. These include:

  • Eating a healthy diet containing lots of fruits, vegetable, calcium and wholegrains and limiting your intake of red and processed meats, and fried foods.
  • Staying physically active and maintaining a healthy weight.
  • Giving up smoking, if you are a smoker.
  • Reducing and/or limit your alcohol intake to less than 2 standard drinks a day.

3. Know your risk factors

Knowing your risk factors and monitoring your own health are important tools in the early detection of bowel cancer. If you notice any symptoms or have concerns relating to your bowel, speak to your GP to discuss your concerns.

Appointments with GPs at Illawarra Medical Centre can be made online or by contacting us on (08) 9208 6400.

Where can I find out more information?

For more information, visit: