A national analysis of adults diagnosed with lung cancer has exposed a striking weakness in the United States’ strategy for finding the disease early: many patients who ultimately develop lung cancer do not qualify for screening under current rules, and most do not receive a low-dose scan before their diagnosis. The study, based on the 2024 National Health Interview Survey, found that only about half of adults with lung cancer met the eligibility criteria recommended by the US Preventive Services Task Force (USPSTF) at the time they were diagnosed. Even more unexpectedly, just one-third reported undergoing low-dose computed tomography, or LDCT, before their cancer was found. The findings suggest that the problem is not simply that people fail to use an available test. The rules themselves may overlook substantial numbers of people at risk, while practical and clinical barriers prevent many eligible individuals from being screened.

Lung cancer is the third most commonly diagnosed cancer in the United States and remains the country’s leading cause of cancer-related death. Its danger is closely tied to timing: tumors discovered after they have spread are much harder to treat successfully, whereas earlier-stage disease may be removed surgically or treated with curative intent. LDCT is designed to detect small abnormalities before symptoms appear. Unlike a conventional diagnostic CT scan, which may cover a broader clinical question and use a higher radiation dose, LDCT uses a carefully calibrated, lower amount of radiation to create images of the lungs. Evidence from the National Lung Screening Trial showed that screening high-risk people with LDCT reduced lung-cancer mortality by about 20 percent compared with chest radiography. Yet the test is useful only if people at elevated risk are identified and return for regular examinations, and if suspicious findings are rapidly evaluated without causing unnecessary invasive procedures.

Under the 2021 USPSTF recommendations, adults between 50 and 80 years old should receive annual LDCT if they currently smoke or quit within the previous 15 years and have accumulated at least 20 “pack-years” of smoking. A pack-year represents smoking one pack of cigarettes per day for one year; someone who smoked two packs daily for 10 years, for example, would have 20 pack-years. The 2021 update lowered the minimum age from 55 to 50 and reduced the smoking threshold from 30 to 20 pack-years, expanding the population eligible for screening. The criteria were intended to improve access and address disparities, but they remain largely dependent on age and cumulative smoking exposure. That creates a blind spot for people who develop lung cancer after lighter smoking histories, long periods since quitting, or no history of smoking at all.

Researchers from the University of California, Irvine, retrospectively examined survey responses from 115 adults aged 50 or older who reported a lung-cancer diagnosis within the previous 10 years. After applying the survey’s statistical weights, the group represented an estimated 638,702 US adults. The analysis used smoking histories to determine whether each person would have qualified for LDCT under the 2021 USPSTF rules at the time of diagnosis. Smoking information was incomplete for four participants, or 3.5 percent of the sample, meaning their eligibility could not be determined. Among the remaining 111 people, 58—52.3 percent in the unweighted sample and approximately 52.0 percent after weighting—met the screening criteria. When people who had never smoked were excluded, eligibility rose to 64.4 percent, or about 66.3 percent using weighted estimates. Even that higher figure means that roughly one in three patients with a smoking history would not have qualified under the current rules.

The study also revealed a sharp difference between having received a CT scan at some point and having received a true screening scan before cancer was diagnosed. Overall, 92 of 110 respondents, or 83.6 percent, said they had undergone LDCT at some time. But only 36 people, or 32.7 percent, reported receiving the scan before their lung-cancer diagnosis; the weighted estimate was 29.6 percent. This distinction matters because CT imaging can be ordered for many reasons, including investigating coughing, chest pain, infection, trauma, or another medical condition. It can also be performed to monitor a known cancer. Such scans may reveal a tumor, but they are not equivalent to systematic screening of people without symptoms. The gap between the two figures therefore suggests that a large share of the imaging reported by patients was diagnostic or follow-up care rather than preventive screening.

The analysis found that women had substantially lower odds of meeting eligibility criteria than men. In the adjusted statistical model, the odds ratio for female sex was 0.31, with a 95 percent confidence interval from 0.12 to 0.77. In practical terms, the result reflects the fact that women in the study generally had accumulated fewer pack-years and had stopped smoking longer ago than men. Women also made up a much larger share of patients who had never smoked: 76.2 percent of never-smokers with lung cancer were female, compared with 43.3 percent among participants with a history of smoking. The researchers observed a possible disparity for non-White participants as well, with an odds ratio of 0.35, although the result narrowly missed conventional statistical significance. When never-smokers were removed from the analysis, demographic factors were no longer significantly associated with eligibility, suggesting that smoking patterns—and the higher proportion of women among never-smokers—helped drive the apparent sex difference.

The findings highlight a biological and epidemiological challenge that fixed smoking thresholds cannot fully address. Cigarette smoking remains the dominant preventable cause of lung cancer, but it is not the only pathway to the disease. Some tumors arise in people who never smoked, including groups in which lung cancer among never-smokers appears to be increasing or is already disproportionately common. Asian women who have never smoked, for instance, have been identified in previous research as an emerging population with elevated risk. Other contributors can include secondhand smoke, occupational exposures, radon, air pollution, inherited susceptibility, and chronic lung inflammation. A rule based only on age and pack-years may therefore be efficient for identifying a major high-risk group while still missing individuals whose risk is clinically meaningful but distributed across several factors. The study’s authors argue that the results add to evidence that current criteria do not capture everyone who will eventually develop lung cancer.

Why eligible people fail to complete screening is less clear from the survey. No demographic characteristic examined by the researchers was significantly associated with receiving LDCT before diagnosis. The reasons may lie in a complicated chain of obstacles: clinicians may not identify eligible patients, patients may not understand that screening is recommended before symptoms appear, and health systems may lack the staff or infrastructure to arrange annual scans and follow-up. Cost, insurance coverage, transportation, time away from work, fear of radiation, stigma surrounding smoking, and anxiety about a possible cancer diagnosis can all reduce participation. Primary-care providers may also be uncertain about the detailed eligibility rules or may prioritize other urgent health needs. Screening is not a one-time event but a recurring process, so a program must maintain contact with patients and ensure that abnormal results are tracked. A single missed appointment can break that chain.

The researchers caution that their estimates should not be interpreted as a perfect measure of screening performance. The survey relied on participants’ memories of their smoking histories, the timing of scans, and the type of CT imaging they received. People may not distinguish an LDCT screening examination from a diagnostic CT performed after symptoms developed, which could make screening uptake appear higher than it truly was. Conversely, incomplete recall of smoking may cause some people to be classified incorrectly as ineligible. The study was cross-sectional and used information collected after diagnosis, so it cannot establish why screening did or did not occur. Because only one year of survey data was analyzed, some racial, ethnic, and language groups were represented by very small numbers, preventing reliable comparisons. Demographic and socioeconomic characteristics such as insurance, income, employment, and residence may also have changed between diagnosis and survey completion, limiting the ability to connect them to earlier screening decisions.

Risk-based screening models could offer one possible way forward. Instead of relying on age and pack-years alone, these models estimate an individual’s probability of developing lung cancer using multiple variables, potentially including smoking intensity, time since quitting, chronic obstructive pulmonary disease, family history, body characteristics, socioeconomic conditions, and other clinical factors. Such approaches might identify some people who fall outside the USPSTF thresholds, including those with lower smoking exposure or additional non-smoking risks. But they also introduce new complications: the necessary data may be missing from medical records, risk calculations can be difficult to explain, and adding more inputs may make programs harder to implement consistently. For now, the new analysis points to a two-part public-health emergency. Screening systems must do a better job reaching people who already qualify, while researchers and policymakers must determine whether eligibility rules should evolve beyond smoking and age. Until both problems are addressed, many lung cancers may continue to be discovered only after the window for the simplest and most effective treatment has begun to close.

Subject of Research: Lung cancer screening eligibility and low-dose computed tomography completion among US adults diagnosed with lung cancer

Article Title: Lung cancer screening eligibility and completion among adults diagnosed with lung cancer: retrospective analysis of 2024 National Health Interview Survey

Article References: Zanazanian I, Chieh AYC, Madan A, et al. “Lung cancer screening eligibility and completion among adults diagnosed with lung cancer: retrospective analysis of 2024 National Health Interview Survey.” Cancer Causes & Control 37, article 148 (2026). Original research article

Image Credits: AI Generated

DOI: 10.1007/s10552-026-02229-x

Keywords: lung cancer screening, low-dose CT, USPSTF guidelines, screening eligibility, health disparities, smoking history, early cancer detection, never-smokers

The study, published in The American Journal of Surgery, analyzed information from the latest version of the Health Information National Trends Survey, or HINTS. Conducted by the National Cancer Institute, HINTS is designed to provide a representative picture of health-related knowledge, behavior and communication across the United States. The survey asks participants about subjects including smoking, alcohol use, diet, exercise and preventive medical care, as well as whether they have discussed screenings for lung, breast and colorectal cancer with healthcare professionals. By examining these responses, the University of Cincinnati team sought to identify how frequently conversations about lung cancer screening occur and which factors may be associated with those discussions.

The central finding was striking because lung cancer screening is recommended for a clearly defined high-risk population, rather than for every adult. The U.S. Preventive Services Task Force recommends annual screening with low-dose computed tomography, commonly called low-dose CT, for adults ages 50 through 80 who have accumulated at least 20 pack-years of smoking and who currently smoke or quit within the past 15 years. A pack-year is a measure of cumulative tobacco exposure calculated by multiplying the number of cigarette packs smoked each day by the number of years a person smoked. Someone who smoked one pack daily for 20 years, or two packs daily for 10 years, would have a 20 pack-year history.

Low-dose CT screening uses an X-ray system to create detailed cross-sectional images of the lungs while exposing the patient to less radiation than a conventional diagnostic CT scan. During the examination, the patient lies on a table that moves through the scanner and briefly holds their breath while images are captured. Unlike many other medical procedures, the test generally requires no intravenous contrast, needles, anesthesia or special preparation. The scan is fast and noninvasive, allowing radiologists to examine lung tissue for small nodules and other abnormalities that may be invisible on a standard chest X-ray or undetectable through symptoms alone.

The technical advantage of screening is its ability to identify disease during a stage when a tumor may remain localized and more amenable to surgery, radiation or other curative treatment. Lung cancer often produces no warning signs until it has advanced, and symptoms such as persistent cough, chest pain, breathlessness or unexplained weight loss can appear only after the disease has spread or begun affecting lung function. Low-dose CT does not guarantee that every cancer will be found, and an abnormal result is not automatically a diagnosis of cancer. Small nodules are common and may reflect infections, scarring or other benign conditions, meaning that some patients require follow-up imaging or additional testing. Even so, screening is intended to shift detection earlier, when treatment options and outcomes are generally more favorable.

Robert Van Haren, MD, senior author of the analysis and an associate professor of clinical surgery at the University of Cincinnati College of Medicine, said the 15% discussion rate is improving but remains alarmingly low compared with other screening practices. Colonoscopy and mammography, he noted, commonly reach discussion or completion rates in the range of 70% to 80%, depending on the measure and population examined. The contrast suggests that the problem is not simply a lack of medical technology, but also a failure to consistently connect eligible patients with information about the technology. A patient cannot weigh the potential benefits and limitations of screening if the subject never enters the consultation room.

The need for greater awareness may be particularly urgent in the Greater Cincinnati region, where smoking remains substantially more common than in the United States overall. Nine of the 10 counties primarily served by the University of Cincinnati Cancer Center have smoking rates above the national average, according to the researchers. Approximately one in three adults in the region smokes, a proportion described by Van Haren as roughly twice the national rate. Higher tobacco exposure increases the number of people who may eventually meet screening criteria, while stigma surrounding smoking-related disease can make some patients reluctant to discuss their risk. Fear of a cancer diagnosis may also lead people to avoid screening, even though early detection is precisely the reason the test is recommended.

Researchers believe the relatively recent arrival of low-dose CT screening may be another barrier. While lung cancer has been screened and diagnosed for decades, modern low-dose CT programs became established within the past 15 years, and public awareness has not necessarily kept pace with the evidence. Patients may confuse screening with a routine chest X-ray, assume the test is invasive, or believe that the absence of symptoms means screening is unnecessary. Some may also be uncertain about whether former smokers remain eligible after quitting. Clear communication from primary care clinicians could help resolve these misunderstandings by explaining the eligibility criteria, the mechanics of the scan, the possibility of false-positive findings and the importance of annual follow-up when screening is recommended.

The University of Cincinnati team is now interviewing primary care doctors and community patients to investigate why these discussions are not occurring more often. Supported by a Cancer Center pilot grant, the project is examining practical and psychological factors that may influence screening conversations, including limited appointment time, uncertainty about guidelines, stigma, fear and the relatively new status of low-dose CT. Understanding whether the main obstacle lies with patients, clinicians, healthcare systems or a combination of all three could help researchers design more effective interventions. Possible solutions may include targeted education, electronic reminders, community outreach and partnerships that connect high-risk adults with screening programs.

Van Haren said the long-term goal is to build stronger community and regional partnerships and launch a focused awareness campaign that encourages eligible people to ask about screening while helping clinicians identify those who qualify. The researchers emphasize that screening is not intended for every adult and should be considered through shared decision-making with a healthcare professional. For people within the recommended age range who have a substantial smoking history and currently smoke or quit within the past 15 years, however, the first step may be as simple as starting a conversation. As lung cancer continues to claim lives after remaining undetected for too long, increasing those conversations could turn an underused preventive tool into an earlier warning system for thousands of Americans.

Subject of Research: Factors associated with patient-clinician discussions about low-dose CT screening for lung cancer.

Article Title: National analysis of factors associated with patient-clinician discussions about lung cancer screening

News Publication Date: 21-Jul-2026

Web References: https://www.sciencedirect.com/science/article/abs/pii/S0002961026003168; https://doi.org/10.1016/j.amjsurg.2026.117131

References: The American Journal of Surgery; Health Information National Trends Survey; U.S. Preventive Services Task Force lung cancer screening recommendations.

Keywords: Lung cancer, low-dose CT, lung cancer screening, smoking, pack-year history, cancer prevention, early detection, patient-clinician communication, public health, computed tomography