Lung Cancer Screening
Lung cancer screening uses a low-dose CT scan to look for lung cancer in people at higher risk, before symptoms develop. Early detection can improve treatment options and outcomes.
What is lung cancer screening?
Lung cancer screening is a test for people at higher risk of lung cancer who do not have symptoms. It uses a low-dose computed tomography scan (LDCT), which is a quick, painless chest scan that uses less radiation than a standard CT.
The goal is to find lung cancer early, when treatment is more likely to be effective. The National Lung Screening Trial (NLST), a large randomized trial of more than 53,000 participants, demonstrated that LDCT screening reduced lung cancer deaths by approximately 20% compared to chest X-ray in high-risk individuals.[1]
Why does it matter?
Lung cancer is the leading cause of cancer death in the United States.[3] Most lung cancers are found at a late stage, when treatment options are more limited. Screening can find cancer earlier, which may improve survival.
The Dutch-Belgian NELSON trial, which followed more than 15,000 participants for 10 years, confirmed a 24% reduction in lung cancer mortality with volume-based LDCT screening in high-risk men.[2]
Who may be eligible for screening?
The U.S. Preventive Services Task Force (USPSTF) updated its lung cancer screening recommendation in 2021 (Grade B). The USPSTF recommends annual LDCT screening for adults who meet all of the following criteria:[3]
- Age 50 to 80 years
- A smoking history of at least 20 pack-years (for example, 1 pack per day for 20 years, or 2 packs per day for 10 years)
- Currently smoke, or quit within the past 15 years
Screening should be discontinued once a person has not smoked for 15 years, or if a person develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery.[3]
The 2021 update expanded eligibility from the prior 2013 criteria (which required age 55–80 and 30 pack-years), broadening access and more than doubling the number of eligible Black and Hispanic individuals.[3,4]
USPSTF: Lung Cancer Screening Recommendation →A conversation, not just a test order
Lung cancer screening works best when it includes a conversation between you and your clinician. This is called shared decision-making. It means reviewing the potential benefits, limitations, and your personal values before deciding whether screening is right for you.
The USPSTF emphasizes that clinical decisions involve more considerations than evidence alone, and that decision-making should be individualized to the specific patient.[3]
Benefits of screening
- LDCT screening can detect lung cancer at an early stage when treatment is more effective[1,2]
- Demonstrated 20–24% reduction in lung cancer mortality in high-risk populations across major trials[1,2]
- The scan is quick (approximately 10–15 minutes), painless, and uses low-dose radiation
- May provide an opportunity to discuss smoking cessation support
Limitations and considerations
- False positives: the scan may find spots that turn out not to be cancer, which can lead to additional testing or worry. In the NLST, approximately 23% of LDCT results were false positive over three screening rounds.[1]
- Overdiagnosis: some cancers found by screening may not have caused symptoms in the person's lifetime[4]
- Radiation exposure, though low with LDCT (average <1.5 mSv per scan)[1]
- Screening does not prevent lung cancer — quitting smoking remains the most important step for reducing lung cancer risk
What to expect during the scan
- The scan takes about 10 to 15 minutes and does not require any preparation or fasting.
- You lie on a table that moves through a CT scanner while holding your breath briefly.
- No needles, dye, or contrast are usually needed.
- Results are reviewed by a radiologist and shared with your ordering clinician.
- If something is found, your clinician will discuss next steps, which may include a follow-up scan in a few months or further evaluation.
Smoking cessation and screening
- Quitting smoking is the single most important thing you can do to reduce your lung cancer risk.
- Screening is not a substitute for quitting, and quitting is beneficial at any age.
- Current smokers should be offered smoking cessation support at the time they start annual screening.[3]
- If you are interested in quitting, talk to your clinician about resources, medications, and support programs.
- Learn more about quitting strategies →
Trusted resources
Questions to ask your clinician
- Am I eligible for lung cancer screening?
- What happens if the scan finds something?
- How often should I be screened?
- What support is available to help me quit smoking?
- Are there other risk factors I should discuss?
References
- National Lung Screening Trial Research Team; Aberle DR, Adams AM, Berg CD, et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011;365(5):395-409. doi:10.1056/NEJMoa1102873
- de Koning HJ, van der Aalst CM, de Jong PA, et al. Reduced lung-cancer mortality with volume CT screening in a randomized trial. N Engl J Med. 2020;382(6):503-513. doi:10.1056/NEJMoa1911793
- US Preventive Services Task Force; Krist AH, Davidson KW, Mangione CM, et al. Screening for lung cancer: US Preventive Services Task Force recommendation statement. JAMA. 2021;325(10):962-970. doi:10.1001/jama.2021.1117
- Jonas DE, Reuland DS, Reddy SM, et al. Screening for lung cancer with low-dose computed tomography: updated evidence report and systematic review for the US Preventive Services Task Force. JAMA. 2021;325(10):971-987. doi:10.1001/jama.2021.0377