肺癌成癌症死亡主因

Chinese scientists estimate that China had 4.3 million new cancer cases in 2015. That's the most representative set of numbers scientists have ever been able to acquire to demonstrate China’s cancer problems. The data collection covers more than a decade and involved 6.5 percent of China's population.

Dr. Chen Wanqing has worked at China's National Central Cancer Registry for 10 years. He says that China's cancer statistics previously were based either on a small sample or a specific year. But this time Chen and his team were able to draw a more complete profile.

"Not only in China but in many other countries of the world, lung cancer is the most common cancer. This is because lungs are the organs that are directly in contact with the external environment through our breathing. Therefore, carcinogenic substances in the air can directly act on our lungs," Dr. Chen said.

The public often wonders what exact impact China's air pollution is generating on their health but Chen says his data doesn't answer the question.

"There will be a long time of contact before carcinogenic substances can cause cancer in the human body, normally a process of 10 to 20 years. Therefore, the current air pollution does not cause the current lung cancer. If we found that lung cancers increase in 10 years, we would then be possible to link it to the air pollution we have today," Dr. Chen said.

Chinese scientists estimate that nearly two thirds of cancer deaths in China could be avoided. People can actively choose to stay away from certain risky environments and lifestyles such as smoking to significantly reduce their chances of getting cancer.

Dr. Gao Shugeng has been a lung cancer specialist for nearly three decades. He says that back in the 1990s, eight in 10 patients who first came to him were already in the terminal stage of cancer. But now, two thirds of his patients are in early stages and have much higher chances of being cured.

"Most early tumours do not develop any symptoms or physical feelings. So, we should definitely avoid doing screening tests too late, say until we have symptoms. We should get a reliable physical examination once a year. Only then can tumours be identified at an early stage," Dr. Gao said.

Gao says doing such common-sense things as regularly exercising, eating a balanced diet and maintaining a positive mood are all effective activities individuals can do to reduce their cancer risks.