Oxford American handbook of oncology. Second Edition. Oxford University Press (2015)
Tobacco smoke contains more than 4000 chemicals, of which more than 50 are known carcinogens. These agents cause DNA gene mutations.
Nicotine causes the addiction to tobacco and hence the exposure to the carcinogens, and it has recently been implicated as potentially contributing to carcinogenesis by activation of nicotinic acetylcholine receptors on bronchial epithelial cells.
- Tobacco use causes 30% of all deaths in the Western world.
- Smoking causes approximately 90% of lung cancers, with a clear dose-response relationship between the risk of developing cancer and cigarette consumption.
- Passive smoking is now well recognized as a danger and cause of smoking-related cancers.
- Male lung cancer deaths have been decreasing since approximately 1990, whereas in females, lung cancer deaths have only recently begun to decline, trends that reflect smoking patterns.
- Smoking is also the major cause of cancers of the larynx, mouth, tongue, pharynx, and esophagus, among others.
- Smoking is a factor in the development of cancer of the pancreas, kidney, stomach, colon, bladder, and cervix.
In an effort to stop exposure to passive smoking and discourage active smoking, some countries have banned smoking in workplaces, restaurants, bars, and other public areas.
Individual smoking cessation adjuncts include counseling (in person or by telephone, such as 1-800-QUIT-NOW) and pharmacological agents (buproprion, varenicline, nicotine replacement), but the most important factor remains patient readiness to quit.