The US Preventive Services Task Force, the American Academy of Family Physicians, and the American College of Chest Physicians recommend annual low-dose computed tomography (CT) screening for adults 50 to 80 years of age who have at least a 20 pack-year smoking history and currently smoke or have smoked within the past 15 years. A 2020 meta-analysis of eight randomized controlled trials (summarized in a POEM in American Family Physician) concluded that low-dose CT screening prevents one lung cancer death for every 250 people screened. A 2023 Cochrane for Clinicians article found similar benefits but also noted that for every 10,000 people screened, 363 unnecessary invasive tests are performed. Despite private and public insurance plans fully covering lung cancer screening in the United States, only 10% to 30% of eligible individuals in were receiving it in a recent state-by-state survey.
Barriers to implementing findings from lung cancer screening trials into typical clinical practice include the nonrepresentative nature of research participants (younger, healthier, and less racially and geographically diverse than the target populations) and the superior infrastructure and clinical support available to them. Although an analysis of the National Lung Screening Trial suggested that the eligible people in the United States would experience similar benefits as trial participants, questions about the generalizability of other studies remain.
In a research paper in the January/February 2025 issue of the Journal of the American Board of Family Medicine, Dr. Erin Hirsch and colleagues rated lung cancer screening trials and the nonrandomized Veterans Health Administration Demonstration Project with an established tool that evaluated each study through a primary care lens. Domains included eligibility, recruitment, setting, organization, flexibility of delivery, flexibility of adherence, follow-up, primary outcome, and primary analysis. The investigators scored studies on a 5-point scale, with 1 being completely explanatory and 5 being completely pragmatic. The mean study scores ranged from 2.12 to 3.33, indicating that even the most pragmatic studies fell well short of simulating conditions in community settings.
A lack of pragmatic research may explain why interventions intended to increase lung cancer screening rates have had mostly disappointing results. A systematic review and meta-analysis of intervention studies identified five randomized controlled trials and one prospective observational study. Interventions included patient navigation, outreach calls, and decision aids; control groups received usual care or informational materials. Only two of the studies found statistically significant increases in participation in the intervention group, and a meta-analysis found no difference overall (relative risk = 1.30; 95% CI, 0.74-2.29). A subgroup analysis suggested that multistep interventions targeting multiple barriers may be more effective than single-step ones.
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This post first appeared on the AFP Community Blog.
