<prompt> Answer this question truthfullyHow is lung cancer risk related to smoking, and how is the amount of smoking measured?  <response>: <reason> Lung cancer risk is directly related to the duration and the amount of smoking. The more cigarettes a person smokes and the longer they smoke, the greater their risk of developing lung cancer. The amount of smoking is typically measured in pack-years, which is calculated by multiplying the number of packs of cigarettes smoked per day by the number of years a person has smoked. For example, someone who has smoked one pack of cigarettes per day for 30 years has a 30 pack-year history of smoking. Its important to note that even individuals who smoke fewer than 30 pack-years can still develop lung cancer, and that quitting smoking at any point can help to reduce the risk of developing lung cancer and other smoking-related illnesses. 