The rate of bowel cancer has risen sharply in young men and women during the past two decades, a study has revealed.
It shows that men and women under 50 are developing the potentially fatal disease more than they used to, and experts are calling for further investigation.
Dr Jamish Gandhi, a surgeon at the Royal Adelaide Hospital who previously worked in New Zealand, has presented his findings to the Royal Australasian College of Surgeons' Annual Scientific Conference in Adelaide this week.
Data from the study was obtained from the National Cancer Registry and linked to population data from 1995 to 2012.
The incidence of bowel cancer, also known as colorectal cancer and covering all cancers of the colon, rectum and large bowel, were categorised by age, gender and location.
The findings showed that the incidence had risen in people aged under 50 years across the various types of bowel cancers, in both males and females.
"We found that among patients aged under 50 years, the incidence of distal colonic cancer in men increased by 14 per cent per decade; the incidence of rectal cancer in men increased by 18 per cent and in women by 13 per cent, per decade, " Gandhi said.
"There were reductions in bowel cancer rates in patients between the ages of 50-79 across certain cancers, however the incidence rate continued to grow once again once people turned 80."
Gandhi said the growing rate of bowel cancer among younger people was concerning, and warranted more attention and investigation.
"Increasing age is noted as a risk for bowel cancer; however we should not be complacent about the risk of bowel cancer just because someone is below the age of 50.
"There are several other risk factors related to family history and lifestyle that may also contribute to a person developing these cancers.
"People need to be aware of what those risk factors are, what signs they should be looking out for, and also what lifestyle changes they can implement to lower their risk."
Early detection is critical, he said. If discovered early the survival rate from bowel cancer is relatively high.
"However, the chance of survival is dramatically reduced the longer it remains undetected."
New Zealand already has one of the highest rates of bowel cancer in the world.
According to the Ministry of Health, 3000 new cases are diagnosed each year and 1200 people die from the disease.
Since late 2011 the Government has offered screening to eligible residents in the Waitemata District Health Board area as part of a pilot programme.
A National Bowel Screening Programme (NBSP) will be progressively rolled out across the country from July this year.
Gandhi said he supported the decision by the government and hoped his study and other evidence would lead to enhanced screening programmes in the future.