Most cancer cases in China are caused by "modifiable environmental factors", including smoking, water contamination and air pollution, according to experts.
In a major report published in The Lancet Oncology, more than 40 specialists warn that China and India, Asia's emerging giants, are facing huge economic and human costs from the disease.
Both nations face a cancer crisis, with smoking, late diagnosis and unequal access to treatment causing large-scale problems. In China, cancer accounted for one in five deaths, ranking second only to cardiovascular disease as the most common cause of death, the study said.
But public awareness of the risk remained extremely low, the experts wrote, tinged by either fatalism or a misplaced faith in traditional medicine.
Funding is also an issue. China spends only 5.1 per cent of its national income on health care - roughly half the rate of European countries - and just 0.1 per cent of this goes specifically to cancer. In the US, cancer accounts for 1 per cent of health spending, or 10 times as much.
Patients in China also need to pay for most cancer treatment themselves, which can lead to catastrophic bills, while urban areas have twice as many cancer care beds than rural areas, even though half of China's population live in the countryside.
"A quarter of all cancer deaths worldwide are in China," said Paul Goss, a Harvard Medical School professor who led the Chinese study. "Some of the main factors responsible for the huge burden of this disease, such as insufficient and unevenly distributed health care resources and public misconceptions about the disease, are barely visible on China's national agenda."
In India, about one million new cancer cases are diagnosed each year, a tally projected to reach 1.7 million in 2035. Deaths from cancer number 600,000 to 700,000 a year, although this figure is also forecast to rise, to about 1.2 million.
The report was due to be presented at an Asian Oncology Summit in Kuala Lumpur at the weekend.