If smoking-related cancers could be eliminated from our society, we would see a significant decline in the annual cancer death rate instead of small but steady increases. Since 1964, the year of the Surgeon General's first report on the health risks of cigarette smoking, strong evidence of the association between smoking and cancer has accumulated. Countless studies have proved that smoking causes lung cancer, and we now know that it substantially increases a person's risk of developing cancer of the larynx, pharynx, oral cavity, esophagus, bladder, kidney, and pancreas.
Additional studies suggest a strong association between smoking and cancer of the cervix.
The risk of developing lung and other smoking-associated cancers is related to total lifetime exposure to cigarette smoke, as measured by the number of cigarettes smoked each day, the age at which smoking began, and the number of years a person has smoked. Likewise, the risk of developing other smoking- related diseases, including chronic lung diseases and coronary heart disease, also increases with the amount of smoking a person has done. The EPA report estimates that ETS is responsible for several thousand lung cancers in nonsmokers each year and, perhaps equally important, links ETS exposure with severe respiratory problems in infants and young children. The good news is that a smoker's risk of developing lung and other cancers can be reduced by quitting. The risk begins to decrease immediately after quitting and continues to decline gradually each year.