Lung Cancer Quiz

See Risk Factors. Option B is correct because tobacco smoking is by far the most important risk factor for lung cancer. Tobacco smoke contains many carcinogens, which are chemicals that can cause cancer, and these damage the cells lining the airways. The risk shows a clear dose-response relationship, meaning that it rises with the amount smoked and the length of time a person has smoked. Secondhand smoke (breathing in other people's smoke) also contributes. In MSD's account, smoking causes the large majority of lung cancers, whereas a minority of cases occur in people who have never smoked or smoked only minimally. Stopping smoking lowers the risk over time but it never returns fully to the level of someone who has never smoked. Smoking is also the largest modifiable risk factor, meaning the one that people and public health teams can do the most about. A neat summary is that the other risk factors are important, but smoking is both the commonest and the most preventable.

• Main risk factor: tobacco smoking is by far the most important risk factor for lung cancer.
• Mechanism: tobacco smoke contains carcinogens that damage the cells lining the airways.
• Dose-response: the risk rises with the amount smoked and the length of time a person has smoked.
• Prevention: smoking is the largest modifiable risk factor.