Wider Lung Cancer Screening Rules Pull In More Smokers, But Who Is Truly at Risk?

Lung cancer remains the deadliest cancer in the United States, killing more people each year than colon, breast, and prostate cancers combined. The single most effective tool for reducing that toll among people who smoke is low-dose computed tomography, or LDCT, a scan that can catch tumors while they are still small and surgically curable. Yet for more than a decade, the benefit of that technology has been rationed by eligibility rules that determined who could be scanned and who could not. A new study published in the Journal of General Internal Medicine examines what happens to the composition of the screening-eligible population when the American Cancer Society’s expanded 2023 guidelines are applied to a nationally representative sample of American adults, and what the predicted lung cancer risk of the newly eligible actually looks like.

The research, led by Adoma Manful of Vanderbilt University Medical Center together with senior authors Jennifer Richmond of Wake Forest University School of Medicine and Meng-Yun Lin, also of Wake Forest, set out to quantify how the guideline change reshapes the pool of people who qualify for annual screening. The team used data from the National Health Interview Survey, a large, publicly available household survey administered by the National Center for Health Statistics at the Centers for Disease Control and Prevention. Because the survey is designed to represent the civilian, noninstitutionalized population of the United States, it allows researchers to translate eligibility criteria written on paper into estimates of how many real people, and which kinds of people, would now be directed toward screening.

To understand why the change matters, it helps to trace the short history of lung cancer screening policy. The landmark National Lung Screening Trial, published in the New England Journal of Medicine in 2011, demonstrated that annual LDCT screening reduced lung cancer mortality by 20 percent compared with chest radiography among people at high risk. That evidence gave rise to the first national screening recommendations, which used a combination of age, smoking intensity measured in pack-years, and years since quitting to define eligibility. The US Preventive Services Task Force later broadened its criteria in 2021, lowering the starting age to 50 and the smoking threshold to 20 pack-years, but it retained a cutoff that excluded anyone who had quit smoking more than 15 years earlier.

The American Cancer Society’s 2023 guideline update broke with that tradition. Drawing on modeling analyses, including work by Landy and colleagues showing that absolute lung cancer risk continues to rise among former smokers with more than 15 quit-years, the Society removed the years-since-quitting restriction entirely. Under the updated recommendation, adults aged 50 to 80 who currently smoke or formerly smoked and have at least a 20 pack-year smoking history are eligible for annual LDCT screening, regardless of how long ago they stopped. The rationale was straightforward: a person’s cumulative exposure does not vanish the moment they extinguish their last cigarette, and former smokers who quit long ago may still carry substantial residual risk.

The new analysis asked a deceptively simple question about that expanded eligibility: among the people swept into the screening pool by the removal of the quit-years limit, what is their predicted risk of lung cancer? This question matters because screening is not free of downsides. LDCT scans detect a large number of incidental findings, including nodules that turn out to be benign, and every follow-up scan, biopsy, or surgery carries its own burden of anxiety, cost, and occasional harm. Screening programs work best when they concentrate on people whose underlying probability of disease is high enough that the expected benefit of early detection outweighs these risks. If the expanded criteria bring in large numbers of people at low predicted risk, the efficiency of the entire enterprise could be diluted.

Using the National Health Interview Survey data, the investigators classified respondents according to the old and new eligibility criteria and estimated the predicted lung cancer risk of each group. The study, which was funded by the National Institute on Minority Health and Health Disparities under award R21MD020158, was reviewed and deemed exempt by the Wake Forest University School of Medicine Institutional Review Board, with all survey participants having provided informed consent. The authors report no conflicts of interest, and the funding agencies had no role in the design, analysis, or decision to publish the findings.

The technical heart of the study lies in how smoking exposure is translated into risk. Pack-years, the standard metric, multiply the number of packs smoked per day by the number of years of smoking, yielding a cumulative dose measure. Risk prediction models developed for screening selection, including the widely used criteria from Tammemägi and colleagues published in 2013, incorporate pack-years alongside age, sex, and other characteristics to estimate an individual’s probability of developing or dying from lung cancer within a defined period. By applying such risk stratification to a nationally representative sample, the researchers could compare the risk profiles of people eligible under the previous rules with those eligible only under the expanded 2023 criteria, providing an evidence-based picture of who the guideline change actually adds.

The findings carry practical weight for clinicians and health systems preparing to implement the expanded guidelines. Primary care practices, which serve as the main gateway to screening, now face a larger eligible population and must decide how to prioritize outreach, shared decision-making visits, and imaging capacity. The study’s risk-based framing offers a way to think about that challenge: eligibility rules define the outer boundary of who may benefit, but predicted risk within the eligible pool varies considerably, and understanding that variation can help clinicians communicate more honestly with patients about the likely balance of benefits and harms. It also informs the ongoing debate about whether screening selection should move away from simple smoking-history thresholds toward more refined, multivariable risk models.

There is an equity dimension as well. Lung cancer screening uptake in the United States has remained strikingly low, with only a small fraction of eligible adults receiving annual scans, and disparities in access and completion persist across racial, geographic, and socioeconomic lines. The National Institute on Minority Health and Health Disparities funding of this work reflects growing recognition that guideline expansions only save lives if the people they cover actually get screened. The authors, who include thoracic surgeon Brian Mitzman of the University of Utah Health and Huntsman Cancer Institute, health economist Richard Nelson of the VA Salt Lake City Healthcare System, and pharmacoepidemiologist Nathorn Chaiyakunapruk, bring a deliberately multidisciplinary perspective to a problem that spans oncology, implementation science, and health policy.

The broader lesson of the study is that screening guidelines are living instruments that must be recalibrated as evidence accumulates. The removal of the quit-years limit was a principled correction grounded in the biology of tobacco-related carcinogenesis, where risk declines slowly, if at all, after cessation. By measuring the predicted risk of the newly eligible population in a nationally representative frame, this research gives policymakers and clinicians a clearer view of the trade-offs embedded in the expanded criteria. As screening programs scale up to meet the larger eligible population, the findings underscore a central tenet of modern cancer prevention: the goal is not simply to scan more people, but to scan the right people, at the right time, with a clear-eyed understanding of who stands to benefit most.

Subject of Research: Predicted lung cancer risk among adults newly eligible for low-dose CT screening under the expanded 2023 American Cancer Society guidelines

Article Title: Expanded American Cancer Society Lung Cancer Screening Eligibility and Predicted Risk

Article References: Expanded American Cancer Society Lung Cancer Screening Eligibility and Predicted Risk. (n.d.). https://doi.org/10.1007/s11606-026-10907-4

Image Credits: AI Generated

DOI: 10.1007/s11606-026-10907-4

Keywords: lung cancer, cancer screening, low-dose CT, American Cancer Society, smoking, pack-years, risk prediction, National Health Interview Survey, screening guidelines, health disparities, preventive medicine, public health