Bowel cancer deaths to rise: study

A global study predicts death rates from rectal cancer will increase in Australia by almost 60 per cent by the year 2035.

Researchers are warning of a sharp increase in Australian deaths from rectal cancer. (AAP)

Death rates from a form of bowel cancer are predicted to increase by almost 60 per cent in Australia by 2035, a study shows.

The global study, published in the International Journal of Cancer on Wednesday predicts death rates from rectal cancer will increase in Australia by almost 59.2 per cent in 16 years.

Meanwhile, America will see a 28 per cent jump and Ireland and Canada increases of 24 per cent.

The underlying reasons for the rise in the high-income countries are "yet to be fully understood", the authors say.

"Possible explanations are changes in the prevalence of risk factors such as increasing body weight and lower physical activity," the study reads.

They conclude the result is "worrisome" and warrants further research.

On the plus side, Australia's rates of colon cancer are expected to fall by around 50 per cent in the same period.

The study found death rates for both colon and rectal cancer are expected to drop globally but the total number of deaths is expected to rise, due to population growth and ageing.

The numbers of deaths were predicted up to the year 2035 by taking a weighted average of the projected mortality rates and then applying the United Nations national population forecasts available for each country.