From the Guidelines
Lung cancer screening is recommended for high-risk individuals, specifically current smokers or those who have quit, aged 50-80 years, with at least a 20 pack-year smoking history, without any restriction on years since quitting. Screening should be done annually using low-dose computed tomography (LDCT) scans. A pack-year is calculated by multiplying the number of packs smoked per day by the number of years smoked. For example, smoking one pack daily for 20 years or two packs daily for 10 years both equal 20 pack-years. Screening should continue annually until the person reaches age 80, develops a health problem that substantially limits life expectancy, or becomes unwilling to undergo curative lung surgery. Before starting screening, patients should have a thorough discussion with their healthcare provider about the benefits, limitations, and potential harms of screening, including false positives that may lead to unnecessary procedures, as stated in the guidelines by the National Comprehensive Cancer Network 1. LDCT screening is effective because it can detect lung cancers at earlier stages when treatment is more likely to be successful, potentially reducing lung cancer mortality by 20-25% in high-risk populations. Smoking cessation counseling should always accompany screening discussions, as quitting smoking remains the most effective way to reduce lung cancer risk. The NCCN guidelines recommend lung cancer screening for individuals with a 20 pack-year history of cigarette smoking, without any limit on years since quitting, as the risk of lung cancer remains elevated even after 15 years since quitting, as supported by studies such as the Framingham Heart Study and the Iowa Women’s Health Study 1. Key considerations for lung cancer screening include:
- Age: 50-80 years
- Smoking history: at least 20 pack-years
- Screening method: annual low-dose computed tomography (LDCT) scans
- Screening duration: until age 80, development of a limiting health problem, or unwillingness to undergo curative lung surgery
- Importance of shared decision-making and discussion of benefits, limitations, and potential harms
- Emphasis on smoking cessation counseling as the most effective way to reduce lung cancer risk.
From the Research
Screening Guidelines for Lung Cancer in Smokers
- The US Preventive Services Task Force recommends annual lung cancer screening with low-dose computed tomography (LDCT) for adults aged 50 to 80 years who have a 20 pack-year smoking history and currently smoke or have quit within the past 15 years 2.
- The American Cancer Society recommends annual lung cancer screening with lung LDCT for individuals aged 50-80 years who are asymptomatic but who currently smoke or have previously smoked 3.
- Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery 2.
Integration of Smoking Cessation and Lung Cancer Screening
- Lung cancer screening programs should include smoking cessation resources, as cessation at any point is beneficial 4.
- Counseling and pharmacotherapy are evidence-based strategies that can help people quit smoking 4.
- Smokers who present for lung cancer screening should be encouraged to quit smoking at each visit, and access to evidence-based smoking-cessation interventions should be provided to all smokers regardless of scan results 5.
Risk of Lung Cancer in Smokers
- There is a high risk of lung cancer among smokers for whom LDCT screening is not recommended, suggesting that prediction models are needed to identify high-risk subsets of these smokers for screening 6.
- The risk of lung cancer is higher in current and former smokers with a history of 20 or more pack-years of smoking, even if they have quit smoking for 15 or more years 6.