Oxford American handbook of oncology. Second Edition. Oxford University Press (2015)
- Tobacco smoking is the most important known carcinogen and the single greatest avoidable cause of premature death worldwide.
- It is associated most commonly with lung cancer but also has a causative role in many other cancers, such as cancers of the esophagus, head and neck, bladder, and pancreas.
- 15% of all cancer cases worldwide and >30% of cases in men from developed countries are attributable to smoking.
- Cigarette smoking has a synergistic (multiplicative) effect on the risk of developing cancer associated with other carcinogens, e.g., asbestos and radon.
- A substantial increase in the global burden of cancer can be expected unless measures to control tobacco distribution and use are strengthened. The growth in global cigarette consumption appears to be greatest among women and in developing countries.
- Smoking cessation reduces the risk of cancer, but programs promoting individual cessation have had only limited success.
- Passive exposure to tobacco smoke also contributes to the overall cancer risk.
- Active smoking is responsible for 85%–90% of cases of lung cancer, with radon exposure, passive smoking, and other environmental and occupational exposures accounting for the rest. The relative risk of lung cancer in a lifelong smoker compared with that of a lifelong nonsmoker is between 10- and 30-fold, depending on intensity and duration of exposure.