Australia has been warned by a leading international cancer expert on a cancer collision course, with an alarming rise in cancer cases expected within the next 2 years unless action has been taken on the country's growing obesity epidemic.

Habits such as smoking and drinking excessive alcohol plus a poor diet and lack of exercise, are some of the contributory factors in the anticipated escalation of cancer cases which are already set to double in the next two decades.

This verdict came from Professor Graham Colditz, an Australian cancer prevention expert based in US. He said that overweight together with obesity costs the country about $21 billion a year, a number that is expected to skyrocket if no action is done today.

Australia's older population in the next 25 years will result to a double figured cancer cases to be diagnosed, Professor Colditz said who will visit NSW this week in order to help the Cancer Council promote cancer prevention.

If we include the consequences of obesity, we will see a major spike in the number of cancer cases. Diabetes and other life threatening diseases are placing immense strain on the wellbeing of Australians and the health system.

But our future is not written on stone. Half of all cancer types are preventable through simple lifestyles and other changes such as quitting smoking, eating healthily and exercising regularly, said Professor Colditz.

Director of health strategies from the NSW Cancer Council, Kathy Chapman, said obesity is a serious matter faced by the country.

One in every four Australian children are already overweigh and obese she said.

We cannot remain still and allow this epidemic to get worse.

You don't have to make a massive lifestyle change to reduce the risk of you developing cancer.

Even small things, like getting off the bus early and start to walk for the rest of the way, can result to big benefits for your health.

Cancer Council NSW is presently running a number of research projects to urge families eat more fruits and vegetables, and understand the long-term benefits of a healthier diet and physical exercises.

For more information about cancer prevention, visit or call the Cancer Council Helpline on 13 11 20.