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.
Brenna, Bilingual Health Educator