Lung cancer rates in China have risen by 30 per cent over the last five years, making the disease the leading killer of men in the world's most populous country, medical experts say.

In China, seven out of every 10 men smoke, and major cities such as Beijing and Guangdong have reported increases in lung cancer cases.

At Shanghai Pulmonary Hospital, an ashtray overflows with damp cigarette butts placed under a no smoking sign.

Dr. Zhou Caicun of the hospital's oncology department said he is embarrassed by the ashtrays at the hospital, which has four floors of lung cancer patients

Zhou is seeing more terminal cases of lung cancer, which he attributes mainly to cigarette smoking. Industrial pollution is another factor.

Smoking is viewed as a pastime in China, like playing cards or mah jong. Chinese men light up in grocery stores, hospitals, and on elevators as if smoking were a cure for cancer, CBC's China correspondent Anthony Germain reported.

Few people understand the importance of quitting smoking, and public education campaigns in China have a long way to go, Zhou said.

Last year, lung cancer killed 600, 000 people in China, and without a reduction in smoking, deaths will rise to a million, he added.

Earlier this week, experts meeting at The Lancet Asia Medical Forum in Singapore said the number of cases of cancer in Asia is also set to rise dramatically by 2020 as the proportion of people over 65 rises.

Projections suggest the number of new cases of cancer in Asia will increase  to 8.1 million by 2020 from 3.5 million in 2002 if current prevention and management strategies aren't changed, the conference heard.