Are more young people getting cancer?
Aimee-Rose Yates never expected to hear that she had metastatic bowel cancer at just 29.
She had spells of diarrhoea prior to her diagnosis in July 2022, but said she didn’t have any other obvious signs pointing to cancer. Instead, her disease was discovered almost by chance.
A family member had been diagnosed with a medical condition associated with an increased risk of colorectal cancer, so it was recommended Yates undergo a colonoscopy.
When they found a “suspicious area”, Yates said she just knew it was cancer.
Then a full-time primary school teacher, Yates had a 6.5cm tumour, diagnosed as adenocarcinoma.
“I was told it was terminal.”
The incidence of a range of cancers in adults under the age of 50 – often referred to as early-onset – has been rising in many parts of the world since the 1990s.
Last month, Kate Middleton, the Princess of Wales, announced she had an unspecified form of cancer at age 42, shortly after 43-year-old actress Olivia Munn posted on social media that she had been diagnosed with breast cancer.
Increased use of screening programmes had contributed in part, but a “genuine increase” in the incidence of several types of early-onset cancers also seems to have emerged, according to international journal Nature.
Consultant medical oncologist Professor Chris Jackson said there’s been an “emerging trend” of incidence rates of cancer in people under 50 slowly increasing over roughly the past 30 years.
As the population goes up, you’d expect to see more cancers, and therefore more cancers in younger people, he said.
And while the increase in incidence rates in young people was “statistically meaningful, and highlights important trends we need to understand”, Jackson noted it was from a low baseline.
“The burden of cancer still primarily falls to those over 60.”
Known risk factors for cancer would account for some, but not all, of the changes being seen in young people, he said.
Things like tobacco and alcohol use, sun exposure, increasing physical inactivity, sedentary lifestyles and obesity were risk factors for cancer, Jackson said.
There were other possible factors that remain areas of active study, and were “speculative rather than certain”, he said, such as whether changes in the gut microbiome, linked to ultra-processed foods and excess antibiotic use, may be playing a role.
Te Aho o Te Kahu (the Cancer Control Agency) deputy chief executive Nicola Hill said while there were concerns that cancer incidence under 50 was increasing globally, “the current available data for New Zealand does not reflect this for cancer overall”.
Health New Zealand data from 2012-21 showed that the rate of cancer registrations (across all disease types) in those aged 0-24 and 25-44 remained relatively stable.
“We continue to monitor trends in cancer incidence to ensure any changes – such as an increase in younger people being diagnosed – is noticed early.”
However, similar to other countries, New Zealand is seeing an increase in colorectal cancer in younger age groups, Hill said.
“It is not clear what is causing this increase, and we will continue to monitor and review both local and international research to better understand this pattern and look for preventable factors.”
Hill said cancer does not discriminate and can occur at any age, so it’s important anyone with concerning symptoms speaks to their GP.