More than 30 percent of cancers can be prevented by lifestyle changes, the World Health Organization said on Friday.

Among key risk factors for cancer are tobacco and alcohol consumption, a diet low in fruit and vegetable intake and lack of physical activity.

"Tobacco use is the most important risk factor for cancer causing 22 percent of global cancer deaths and 71 percent of global lung cancer deaths," the UN health agency says.

Halting tobacco use, for instance, could therefore help cut cancer mortality rates.

According to latest available figures dating to 2008, cancer caused 7.6 million deaths worldwide during the year, making up about 13 percent of global mortality.

Lung, stomach, liver, colon and breast cancers caused the most fatalities.

About 70 percent of all cancer deaths in 2008 occurred in low- and middle-income countries.

The WHO projected that deaths from cancer will continue rising, and will hit an estimated 13.1 million in 2030.