Pack year smoking History
For example, some studies suggest that women are more susceptible to the carcinogens in cigarettes, because women appear to develop lung cancer after fewer pack-years of smoking than do men.
Jill smoked 1 pack of cigarettes daily for 20 years. She has a 20 pack-year history of smoking.
Frank smoked 2 packs of cigarettes daily for 20 years. He has a 40 pack-year history of smoking.
Eleanor smoked 10 cigarettes (1/2 pack) per day for 20 years. She has a 10 pack-year history of smoking.
Lung Cancer Screening
Recently, doctors have studied the number of pack-years of smoking to determine who should be screened for lung cancer. Studies suggest that people who have a 30 pack-year history of smoking, are between the ages of 55 and 80, and continue to smoke or have quit in the past 15 years, are candidates for CT lung cancer screening. Studies using these criteria have found that the mortality rate from lung cancer could be cut by 20% if people meeting this criteria undergo screening.
Pack-Years and Smoking Risk
In general, the more pack-years you have smoked, the greater the chance of getting cancer. That said, lung cancer occurs in never smokers, and many people chain smoke for decades without getting cancer. Though people aren't statistics, you might be wondering about the likelihood that you will develop lung cancer.
Pack-Years and Heart Disease Risk
The number of pack-years someone has smoked is correlated not only with lung cancer, but with heart disease, lung diseases such as COPD, and others.
While the number of pack-years a person has smoked is a useful tool in determining risk, it is not foolproof. There is some controversy that the duration of smoking may be an important factor to consider, especially in determining lung cancer risk.
Blackmon, S., and S. Feinglass. The United States Preventive Services Task Force recommendations for lung cancer screening. Thoracic Surgery Clinics. 2015. 25(2):199-203.
Guaraldi, G. et al. Lung and Heart Diseases Are Better Predicted by Pack-Years than by Smoking Status or Duration of Smoking Cessation in HIV Patients. PLoS One. 2015. 10(12):e0143700.
Janjigian, Y. et al. Pack-years of cigarette smoking as a prognostic factor in patients with stage IIIB/IV non-small cell lung cancer Cancer. 2010. 116(3):670-5.