NZ bowel cancer rates dropping – Expert reaction

Increasing economic development is linked with growing rates of bowel cancer, but some high-income countries – including New Zealand – seem to be exceptions, according to a global cancer study.

human intestinesDrawing on data from 184 countries, researchers from the International Agency for Research on Cancer found that rates of bowel cancer increased with levels of economic development.

However,  the authors noted that some countries with the highest levels of economic development were now showing decreases in the rates of bowel cancer and deaths from bowel cancer. New Zealand and Australia were included in this group along with Iceland, France the USA and Japan.

The authors say the downward trend seen in these countries is likely linked to improved detection and treatment of the disease. But the findings point to a much greater disease toll in low and middle income countries in the years to come, particularly for emerging economies, they warn.

They also acknowledge that some of the countries showing decreasing trends still have colorectal cancer rates among the highest in the world.

The findings are published in the journal Gut today.

You can access the full research and press material on

The SMC collected the following expert commentary.

Assoc Prof Diana Sarfati, Co-Head of Department, Department of Public Health, University of Otago, Wellington, comments:

“Trends in both incidence and death rates from bowel cancer are decreasing in New Zealand. It is not clear what the specific drivers are for these trends, but at least some of the change appears to be driven by factors that occur in early life. People born in more recent times have lower risk of bowel cancer at a given age than those who were born in earlier years. There have also been substantial improvements in the treatment of bowel cancer over the last few decades.

“The downward trends are not equally spread though the population, with incidence and mortality rates decreasing far more quickly for NZ Europeans than for Maori and Pacific groups.

“Once a national bowel cancer screening programme is in place, we should expect to see death rates from bowel cancer declining further.”