From the Guidelines
Annual low-dose CT chest screening is recommended for adults aged 55-80 years with a 30 pack-year smoking history who currently smoke or have quit within the past 15 years. This recommendation is based on the most recent and highest quality evidence from the American College of Radiology Appropriateness Criteria 1 and the U.S. Preventive Services Task Force recommendation statement 1. The screening should continue until the person has quit smoking for 15 years, reaches age 80, or develops a health problem that significantly limits life expectancy or the ability to undergo curative lung surgery.
The benefits of low-dose CT chest screening include detecting lung cancer at earlier, more treatable stages, potentially reducing lung cancer mortality by 20-25% 1. The low radiation dose used (approximately 1.5 mSv) minimizes exposure risks while maintaining diagnostic quality. However, patients should understand that false positives can occur, potentially leading to additional testing, and that not all lung cancers will be detected.
Key considerations for implementing low-dose CT chest screening include:
- Screening should be performed at centers with experience in lung cancer screening and treatment
- Screening should be accompanied by smoking cessation counseling for current smokers, as quitting smoking remains the most effective way to reduce lung cancer risk
- Patients with additional risk factors for lung cancer, such as radon exposure, occupational exposure, cancer history, family history of lung cancer, history of COPD, or history of pulmonary fibrosis, may also benefit from screening, although the evidence is less clear 1.
Overall, the evidence supports the use of low-dose CT chest screening as a valuable tool for reducing lung cancer mortality in high-risk populations, and healthcare providers should prioritize this screening for adults who meet the recommended criteria.
From the Research
CT Chest Recommendations for Smokers
- The US Preventive Services Task Force recommends annual screening for lung cancer with low-dose computed tomography (LDCT) in 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.
- A study found that lung cancer risk decreases gradually with years since quitting (YSQ) in 30+ pack year former smokers, suggesting that a range of upper limits on YSQ may be supportable for LDCT screening 3.
- The Society for Research on Nicotine and Tobacco and the Association for the Treatment of Tobacco Use and Dependence recommend integrating evidence-based smoking-cessation treatment with lung cancer screening, and providing access to smoking-cessation interventions for all smokers regardless of scan results 4.
- A survey of older smokers found that most are interested in and positive about LDCT, and that cognitive aspects of participation in screening are key to increasing the uptake of lung cancer screening among high-risk smokers 5.
- A meta-analysis of 11 trials found that LDCT screening reduces lung cancer-related mortality by 21% compared to control groups, and that there is probably no difference in subgroups for analyses by control type, sex, geographical region, and nodule management algorithm 6.
Eligibility Criteria
- Adults aged 50 to 80 years with a 20 pack-year smoking history and currently smoke or have quit within the past 15 years are eligible for annual LDCT screening 2.
- Former smokers with 30+ pack-years are eligible for LDCT screening within 15 years of quitting 3.
Screening Frequency and Duration
- Annual screening is recommended for adults aged 50 to 80 years who meet the eligibility criteria 2.
- The duration of screening ranges from 1 year to 10 years in different trials 6.