The total of cancer cases in Asia is projected to balloon from 4.5 million in 2002 to 7.1 in 2020, straining health systems in countries that can least afford it, according to experts quoted by media Monday.

Speaking at Lancet Asia Medical Forum in Singapore, Richard Horton, editor of the British medical journal Lancet, warned Asia -- which already has most of the world's stomach and liver cancer cases -- may account for about 58 percent of all cancer cases in the world by then.

Donald Maxwell Parkin, a research fellow at Oxford University in Britain, also stated that Asia may account for about 65 percent of all cancer cases by 2050.

"Population growth will increase the number of cases," Parkin said at the start of the two-day forum.

Once considered a disease of wealthy nations, cancer is increasingly afflicting developing countries due to tobacco and alcohol abuse, unhealthy diets and the lack of exercise, experts said.

Cancer of the lungs, stomach and liver are the biggest problems in Asia followed by breast and colon cancers, they noted.

"This will put a tremendous burden on patients, their families and the health care system in each country," said Khaw Boon Wan, Singapore's minister of health.

"Singapore will not be spared. Cancer is already our top killer and we are bracing ourselves for the disease burden to increase as our population ages," he warned.