The more people smoke, the longer they
smoke, and the earlier they start smoking, the more likely they are to develop
lung cancer. Smokers of two or more packs a day have lung cancer mortality
rates 15 to 25 times greater than non-smokers. If smokers stop smoking before
cancer has started, their lung tissue tends to repair itself, even if there
were already precancerous changes. Former smokers who haven’t smoked for 15 or
more years have lung cancer mortality rates only somewhat above those for
non-smokers.
