Smoking and Lung Cancer

• Cigarette smoking is the leading risk factor for lung cancer.
• In the U.S., cigarette smoking is linked to 80% to 90% of cancer deaths.
• Tobacco smoke is a mixture of more than 7,000 chemicals, of which at least 70 cause cancer in humans.

• People who smoke cigarettes are "15 to 30 times more likely to get lung cancer or die from lung cancer" compared to people who do not smoke.
• The more cigarettes that are smoked each day and the more years a person smokes, the higher the risk of getting cancer. This means that the risk of lung cancer increases with the number of cigarettes that are smoked each day and the number of years that one has smoked. Quitting at any age lowers the risk of developing lung cancer.
• Heavy smoking refers to a smoking history of 30 pack-years or above. One pack-year is an average of one cigarette pack every day for one year.
•  55% of deaths in women due to lung cancer and 70% of deaths in men due to lung cancer are a result of smoking.