Smoking Is a Major Cause of Cancer
Cigarette smoking causes heart disease, respiratory problems, and at least 15 types of cancer. It is responsible for 80 to 90 percent of lung cancers, the leading cause of cancer deaths in the United States.
The good news is that lung cancer is the most preventable form of cancer. People who don’t smoke have a much lower risk of developing lung cancer, and smokers who quit reduce their risk significantly.