December 10th, 2024

University of Otago research prompts calls to lower bowel cancer screening age in New Zealand

Rising colorectal cancer rates among young New Zealanders, particularly Māori, have sparked new recommendations for earlier screening.

The study also addresses diagnostic delays, particularly among younger patients, which contribute to more advanced disease and poorer outcomes.
The study also addresses diagnostic delays, particularly among younger patients, which contribute to more advanced disease and poorer outcomes.

A comprehensive study from the University of Otago, Christchurch, is urging a reduction in the starting age for bowel cancer screening across New Zealand following an alarming increase in colorectal cancer rates among younger demographics. The study, published in the UK’s Biomed Central medical journal, highlights a significant 26% rise per decade in early onset colorectal cancer (EOCRC) over the last 20 years, contrasting with decreasing rates in older age groups.

The research encompassed data from 2000 to 2020, tracking 56,761 cases of colorectal cancer, of which 3,702 were early onset. The analysis revealed a particularly stark increase among Māori under 50, where rates escalated by 36% per decade—exceeding the growth in the overall population.

Dr Oliver Waddell, the lead author and a member of the campus's Department of Surgery, expressed deep concern over the disproportionate impact on Māori, according to a media release from the university.

"This is of grave concern because once diagnosed with colorectal cancer, Māori are more likely to die from their disease than non-Māori, and also more likely to be diagnosed with stage 4 advanced disease, possibly due to delayed diagnosis and inequitable access to cancer treatment," he said.

The findings have prompted calls to lower the national bowel cancer screening age, currently set at 60 for non-Māori and 50 for Māori, to 45. This change aligns with recent adjustments in countries like the USA and Australia and is supported by evidence suggesting significant benefits from early detection.

Dr Waddell emphasised the necessity for increased screening: "Unfortunately, in over a third of patients diagnosed with bowel cancer under the age of 50, by the time symptoms have developed, the cancer has already spread to stage 4 disease, so we need to find these cancers earlier before it’s too late for a cure."

The study also addresses diagnostic delays, particularly among younger patients, which contribute to more advanced disease and poorer outcomes. It recommends enhancing patient education on when to seek medical attention and increasing endoscopy capacity to match international standards.

These findings come at a critical time as New Zealand contends with one of the highest rates of bowel cancer globally, with over 3,000 cases diagnosed annually. The study projects a concerning future, with numbers potentially doubling in the over-80 age group by 2040, posing a significant challenge to the health system.

The call for change reflects a broader need for adaptations in healthcare policies to better manage emerging trends in disease patterns and demographics.