Benefits of Lung Cancer Screening
Other than quitting smoking, early diagnosis of lung cancer is currently the most effective way of reducing lung cancer mortality because the treatment of late-stage disease has little impact.1 In addition to awareness of risk factors and prompt referral, screening with low-dose computed tomography (LDCT) has proven to improve early diagnosis.
LDCT is a computed tomography (CT) scan technique that combines special x-ray equipment with sophisticated computers to produce multiple, cross-sectional images of the inside of the body. Randomized trials have demonstrated a significant association between reduced lung cancer mortality and lung cancer screening.
In the National Lung Screening Trial (NLST), a 2-year research study funded by the National Cancer Institute, researchers observed a 20% decrease in mortality from lung cancer in the low-dose CT group as compared with the radiography group.2
The NLST study enrolled 53,454 persons at high risk for lung cancer. Participants were randomly assigned to undergo 3 annual screenings with either low-dose CT (26,722 participants) or single-view posteroanterior chest radiography (26,732 participants).
In another large-scale study involving 13,195 men and 2594 women with a minimum follow-up of 10 years until 2015, researchers also found that lung cancer mortality was significantly lower among those who underwent volume CT screening than among those who underwent no screening.3
Centers for Medicare & Medicaid Services (CMS), the federal agency that administers the Medicare program, determined in February 2022 that the evidence is sufficient to expand coverage for lung cancer screening with LDCT to improve health outcomes for people with lung cancer. In the CMS decision, LDCT is mentioned as the only recommended screening test for lung cancer.4
Current Guidelines for Lung Cancer Screening
The current guidelines on lung cancer screening for high-risk people include adherence to the U.S. Preventive Services Task Force (USPSTF) Lung Cancer Screening recommendations and the use of Lung Imaging Reporting and Data System (Lung-RADS).5
The USPSTF is an independent, volunteer panel of national experts in disease prevention and evidence-based medicine. For lung cancer, USPSTF provides information about the optimal age at which to begin and end screening, the optimal screening interval, and the relative benefits and harms of different screening strategies, including risk factor–based strategies using age, pack-year smoking history, and years since quitting smoking for former smokers, compared with modified versions of multivariate risk prediction models.
In a 2021 report, USPSTF recommends annual screening for lung cancer with 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. 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.6
In clinical practices, a classification system called Lung-RADS provides guidance for clinicians regarding which findings are suspicious for cancer and the suggested management of lung nodules detected.
Developed by American College of Radiology (ACR), the Lung-RADS system helps minimize the uncertainty and variation regarding the evaluation and management of lung nodules, standardize the reporting of screening results, and decrease confusion in lung cancer screening result interpretation.
For example, based on the Lung-RADS categorization, a solid nodule larger than or equal to 6 mm and smaller than 8 mm at baseline is considered “probably benign,” with a recommended management of 6-month LDCT. In comparison, solid nodules larger than or equal to 15 mm are “very suspicious” and a range of managements are recommended.7
To learn more about lung cancer screening, read Identifying Best Practices and Gaps in Early-Stage Lung Cancer: From Screening and Early Detection Through Resectable Disease Treatment.
References
- Baldwin DR, Callister MEJ. What is the Optimum Screening Strategy for the Early Detection of Lung Cancer? Clinical Oncology. 2016;28(11):672-681.
- National Lung Screening Trial Research Team. Reduced lung-cancer mortality with low-dose computed tomographic screening. New England Journal of Medicine. 2011;365:395-409.
- de Koning HJ, van der Aalst CM, de Jong PA, et al. Reduced lung-cancer mortality with volume CT screening in a randomized trial. New England Journal of Medicine. 2020;382:503-513.
- CMS Expands Coverage of Lung Cancer Screening with Low Dose Computed Tomography. Feb. 10, 2022. https://www.cms.gov/newsroom/press-releases/cms-expands-coverage-lung-cancer-screening-low-dose-computed-tomography. Accessed March 15, 2022.
- Collar N, O’Neill B, Parham K, et al. Identifying Best Practices and Gaps in Early-Stage Lung Cancer: From Screening and Early Detection Through Resectable Disease Treatment. Journal of Oncology Navigation & Survivorship. February 2022 Vol 13, No 2.
- US Preventive Services Task Force. Lung Cancer: Screening. www.uspreventiveservicestaskforce.org/uspstf/recommendation/lung-cancer-screening. Accessed March 15, 2022.
- American College of Radiology. Lung CT Screening Reporting & Data System (Lung-RADS). www.acr.org/Clinical-Resources/Reporting-and-Data-Systems/Lung-Rads. Accessed March 15, 2022.
