The rise of bowel cancer in younger Australians

Australia has one of the highest rates of bowel cancer in younger patients in the world, with diagnoses in people under 40 more than doubling since 2000 and specialists still searching for answers.

While genetics play a role, most younger patients diagnosed with bowel cancer have no family history of the disease.

Epworth HealthCare colorectal surgeon Adjunct Professor Satish Warrier, who practises at Epworth Freemasons and Epworth Richmond, said the increase in bowel cancer diagnoses among younger patients is unlikely to be due to a single cause.

“The evidence points to a combination of factors including diet, obesity, smoking, microplastics, childhood exposure to certain gut bacteria leading to changes in the gut microbiome, and increasing consumption of ultra-processed foods,” he said.

“One of our biggest concerns is that younger people often don't see themselves as being at risk of bowel cancer.

“Symptoms may be dismissed, explained away or attributed to other conditions, which can delay diagnosis and treatment.”

Prof. Warrier welcomed the recent decision to lower the eligibility age for the National Bowel Cancer Screening Program from 50 to 45.

“It’s an important acknowledgement that bowel cancer is no longer solely a disease of older Australians,” he said.

“But we also need greater awareness among both the community and healthcare professionals because bowel cancer can present in many different ways.

“For example, lethargy and fatigue due to iron deficiency can be symptoms of bowel cancer, but in some patients those signs may initially be attributed to other causes.”

Sriram, 42, had no family history of bowel cancer when he noticed a change in his bowel habits and blood in his stool.

Like many younger patients, he initially assumed the symptoms were linked to diet and wasn't overly concerned.

His symptoms persisted and he sought medical advice. Initially diagnosed with inflammatory bowel disease, he underwent a series of tests and treatments before receiving a bowel cancer diagnosis in November last year.

“It was a huge shock for me,” he said.

“I thought I was going to be told my medication was changing, and instead I was told I had cancer. My mind went blank and I couldn't process anything after that.

“I went from planning a trip to Singapore to see my parents, to starting chemotherapy.”

Sriram has since undergone surgery to remove his entire large intestine and will have further surgery later this year.

Despite the diagnosis, he considers himself fortunate.

“My cancer hadn't spread, and I am grateful I had a good GP who listened to me and took action,” he said.

Bowel cancer treatment requires experts across multiple disciplines working together to achieve the best possible outcomes for younger patients. Prof. Warrier acknowledged the dedication and collaboration of all involved at Epworth, including oncology, radiology and pathology, as well as nursing and allied health staff and other specialised services.

Prof. Warrier said bowel cancer symptoms can range from obvious signs such as blood in the stool to less well-known symptoms including changes in bowel habits, abdominal cramps, bloating, discomfort, iron deficiency and extreme fatigue.

“The earlier we diagnose bowel cancer, the better the outcome for the patient,” he said.

“Targeted treatments such as immunotherapy, combined with chemotherapy and surgery where appropriate, can be very effective. However, the later bowel cancer is diagnosed, the greater the risk it has already spread.

“If something doesn't feel right, don't ignore it. You won't regret speaking to your GP and asking questions.”