You probably know that smoking cigarettes is associated with a higher risk of lung cancer — but do you know how much higher? Cigarette smoking is directly responsible for an estimated 90 percent of all lung cancers. Smokers are between 15 and 30 times more likely to get or die from lung cancer than non-smokers. Plus, having certain diseases that are associated with smoking (like emphysema) can increase your risk even further. If you’ve never smoked, don’t start.