A recent analysis found a decrease in the overall incidence of colorectal cancer in New Zealand, but an increased incidence of rectal cancer in those under 50 years of age.
Among individuals aged under 50 years, the incidence of distal colonic cancer in men increased by 14% per decade. The incidence of rectal cancer in men increased by 18% and in women by 13%. In those aged 50-79 years, there was a reduction in incidence per decade of proximal, distal, and rectal cancers in both sexes. In individuals aged 80 years and older, proximal cancer incidence per decade increased by 19% in women and by 25% in men; among women, the incidence of distal colonic cancer decreased by 8%, as did that of rectal cancer.
The study's investigators noted that New Zealand has among the highest rates of colorectal cancer in the world, with a median annual age-standardized rate per 10,000 of 55 for men and 44 for women. A national colorectal cancer screening programme has been piloted, but it has yet to be introduced.
The findings are published in the British Journal of Surgery.