More details about disease will help experts target information, treatment

China has set up the world's largest cancer registry through its 308 leading hospitals, covering more than 300 million people, said registry director Chen Wanqing.

At least 3 million people develop cancer each year in China, and the registry is expected to expand to include 40 percent of the nation's population of 1.36 billion by 2020.

It will register more medical institutions as they become qualified sites for cancer surveillance, Chen said.

"The more people the registry covers, the more precisely we will understand the rising epidemic," Chen said. "That will help experts and health authorities come up with evidence-based and more-targeted intervention programs."

In general, the registry collects information such as new cancer cases, deaths, and courses of treatment to build up an overall national picture. To date, medical costs have not been included.

Cancer claims 2.2 million lives in China and costs at least 100 billion yuan ($16 billion) each year, previous expert estimates have shown.

Well-designed intervention and health communication, according to Chen, "could work well to curb a rising trend of cancer".

The World Health Organization said about one-third of cancer cases could be prevented and many more could be controlled. Many cancers are linked to lifestyle choices, the environment, or family history.

According to Chen, preventable cancers account for nearly 60 percent of China's total cases, such as hepatitis C sometimes leading to liver cancer.

Smoking is another major risk factor for cancer and accounts for 22 percent of the preventable cases in China, he said, citing data from the registry. Some others are associated with unhealthy life habits such as a diet high in salt or fat, and little physical exercise.

Based on these findings, enabled by the registry, "we can draw clear conclusions that China's cancer epidemic could be well-harnessed with better control of infections, smoking and alcohol limits, and promoting a healthy lifestyle among the public", Chen said.

"We will keep including more people in the cancer registry to aid more advanced research and more effective interventions," he said.

Some European countries have registries that cover their entire population, and China still needs to do more to achieve that, he added.

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