There were an estimated 14.1 million new cancer cases worldwide in 2012, mostly in developing countries, according to a new report from the World Health Organization.

In comparison, in 2008 there were 12.7 million new cases cases, the WHO's International Agency for Research on Cancer said. About 8.2 million cancer-related deaths occurred in 2012 compared with 7.6 million in 2008.

India Smoking

More people are also smoking in developing countries, one of the factors driving up cancer cases and deaths. (Manish Swarup/Associated Press)

Dr. David Forman is the head of the agency's cancer information section, which compiled the data.

"The world's population is both increasing and it's getting older and as a consequence of that one sees in many populations more people at risk of cancer," Forman said in an interview with CBC News Thursday from Lyon, France. "I think what's different on the world stage is that a greater proportion of these cancers are now occurring in developing regions of the world."

More than half of all cancers (56.8 per cent) and cancer deaths (64.9 per cent ) in 2012 occurred in less developed regions. In developing countries, the living longer combined with a change in lifestyle, such as poor diet and obesity, can increase the risk of breast cancer and bowel cancer to some extent, Forman said. More people are also smoking in developing countries.

A shift towards lifestyles typical of industrialized countries also leads to a rising burden of cancers associated with reproductive and hormonal risk factors, such as having children later in life,  the report's authors said.

The most commonly diagnosed cancers worldwide were those of the lung (1.8 million, 13.0 per cent of the total), breast (1.7 million, 11.9 per cent), and colorectal (1.4 million, 9.7 per cent).

The most common causes of cancer death were in the lung (1.6 million, 19.4 per cent of the total), liver (0.8 million, 9.1 per cent), and stomach (0.7 million, 8.8 per cent).

Breast cancer was the most common cause of cancer death among women (522,000 deaths in 2012).

Clinical advances to fight breast cancer haven't yet reached less developed countries, Forman said in a release.

The researchers also called for HPV vaccination and well-organized national screening and treatment programs for cervical cancer in less developed countries.