Health & Medicine, New Zealand (Commonwealth Union) – To counteract the alarming surge in colorectal cancer cases among individuals under 50 and to curtail the corresponding mortality rate, a team of researchers from the University of Otago advocates for a reduction in the screening age for this condition in New Zealand.
Outlined in an editorial featured in the recent edition of the New Zealand Medical Journal, Dr. Oliver Waddell, Dr. Tamara Glyn, and Professor Frank Frizelle underscore that New Zealand, aligns with a global pattern wherein an escalating number of people below the age of 50 are being diagnosed with bowel cancer, referred to as early onset colorectal cancer.
Statistics spanning from 1995 to 2012 reveal a 14 percent escalation in colon cancer cases among New Zealand men under 50, and a parallel increase of 13 percent among women in the same age group.
The situation is particularly distressing for the Māori population, as they bear a disproportionately high burden of early onset bowel cancer. Among Māori females, 30 percent of bowel cancer cases occur before reaching the age of 50, with a corresponding figure of 25 percent among Māori males.
These findings mirror research outcomes from diverse regions including Australia, the United States, Canada, the United Kingdom, France, and Asia. In these countries, an unmistakable surge in bowel cancer incidents among those under 50 is evident. The United States, for example, has witnessed a doubling of early-onset bowel cancer cases since the 1990s, and projections estimate that by 2030, over 10 percent of colon cancers and nearly 25 percent of rectal cancers will affect individuals under 50.
Countries that commence screening at age 40 have seemingly sidestepped the impacts of this burgeoning trend, according to Dr. Waddell.
In contrast, New Zealand, where bowel cancer ranks as the second most deadly form of cancer, maintains one of the world’s highest screening ages. Presently, the National Bowel Screening Programme is exclusively accessible to individuals aged 60 to 74. In Australia, the screening for bowel cancer commences at age 50, and individuals as young as 45 can request access to this screening procedure.
An analysis of global patterns in the incidence rates of early onset colorectal cancer, encompassing five continents, revealed a mere trio of nations where such rates were on a decline. Among these three countries, Italy and Austria, both of which have been conducting patient screenings from as early as age 40 or 44 since the 1980s, as Dr. Waddell elucidates, stand out.
As per the guidelines outlined by the American Cancer Society, the initiation of screening is advised at 45 years of age. Their computational models project a potential enhancement of 22 to 27 years of life gained per 1,000 individuals subjected to screening.
“If the age of eligibility for screening in New Zealand were lowered to 40 or 45 it would be likely to result in a proportional decrease in the diagnosis of early onset colorectal cancer as seen in countries with a lower age of screening.”
From 1995 to 2020, the prevalence of early onset bowel cancer in New Zealand revealed that 45 percent of cases fell within the age range of 45 to 49.
“This means that almost half of those early onset cases may either be prevented or diagnosed earlier if screening was lowered to 45, and more so if reduced to 40,” he explained.
The surge in occurrences is believed to primarily stem from environmental influences, possibly intertwined with shifts in the gut’s bacterial composition. While a multitude of loosely connected factors have been proposed as potential contributors to the growing prevalence of bowel cancer among younger individuals – including evolving patterns in obesity, sedentary behaviors, and smoking – the exact cause remains unconfirmed.
