ALMOST 40 per cent of cancer deaths in Australia are potentially avoidable, a study has found.
Researchers estimate that about 17,000 Australian lives may be saved each year, mostly through lifestyle changes, such as giving up smoking, eating better, exercising more, reducing alcohol intake and covering up in the sun.
A study by QIMR Berghofer Medical Research Institute analysed Australian cancer deaths attributed to 20 modifiable risk factors accepted internationally as being causes of cancer.
It used data from the Australian Institute of Health and Welfare, and the Australian Bureau of Statistics to estimate how many cancer deaths in 2013 were caused by modifiable factors and were therefore preventable, at least in theory.
Lead researcher David Whiteman, head of QIMR Berghofer's cancer control group, said they found modifiable risk factors were conservatively implicated in 41 per cent of cancer deaths among Australian men and 34 per cent in women.
"The proportions of potentially preventable cancer deaths are higher among men than women because, on average, men smoke and drink more, spend more time in the sun and don't eat as well," Professor Whiteman said.
Almost a quarter of all cancer deaths in Australia were caused by smoking, including passive smoking, accounting for about 10,000 of the country's 44,000 cancer deaths in 2013.
Professor Whiteman said smoking had been implicated in more than a dozen cancers, including some ovarian cancers.
He said other major modifiable cancer-causing risk factors included infections, such as the sexually transmitted human papillomavirus, poor diet and being overweight or obese, which each made up about five per cent of all Australian cancer deaths annually.
The cancers responsible for the largest numbers of potentially preventable deaths are those of the lung, bowel, skin, liver and stomach.
Professor Whiteman said the study accounted for cancer deaths over and above the "background genetic risk" within the Australian population.
"While in many cases cancer is tragically unavoidable, this study highlights what we've known for years: cancer isn't always a matter of genetics or bad luck."
The research did not account for other known environmental cancer causes, such as air pollution and radiation exposure, because of the difficulty in quantifying the risk.
Although elderly Australians, aged 75 and older, were included in the overall data, Professor Whiteman said the percentage of potentially avoidable cancer deaths was higher - at 43 per cent - when calculated in people aged up to 75.
Professor Whiteman said the aim of the research was not to blame individual patients for their lifestyle choices, but to provide a helpful guide to people to reduce their risk of cancer - the biggest cause of death in Australia.
The study was published recently in the International Journal of Cancer.
For recommendations to cut your chances of developing cancer: qimrberghofer.edu.au/reduce-your-cancer-risk-guide