Smoking. Smoking is the number one cause of lung cancer. It causes about 90 percent of lung cancer cases. Tobacco smoke contains many chemicals that are known to cause lung cancer.
More people die from lung cancer than any other type of cancer. Cigarette smoking is the number one risk factor for lung cancer; it's responsible for 87 percent of .
Cigarette smoking is the cause of over 90 per cent of lung cancer cases. The National Cancer Centre Singapore (NCCS) shares the other causes and risks.