Risk-Adapted Lung Cancer Screening Could Refine Care for Former Smokers
Posted: Tuesday, January 6, 2026
In a recent cohort study published in JAMA Network Open, Clara Frick, MSc, and colleagues proposed a more individualized approach to lung cancer screening for former heavy smokers by tailoring the age at which screening begins according to the time since smoking cessation. Using data from the UK Biobank, the investigators found that former smokers reach lung cancer risk levels comparable to current smokers at substantially older ages, depending on how long ago they quit. The main goal of the study was to move beyond the current “all-or-nothing” eligibility framework used by the U.S. Preventive Services Task Force (USPSTF) and to define risk-adapted screening starting ages that more accurately reflect an individual’s lung cancer risk.
Background
Current USPSTF guidelines recommend annual low-dose computed tomography screening for adults aged 50 to 80 years with at least a 20 pack-year smoking history who either continue to smoke or quit within the past 15 years. This approach assumes a uniform screening start age of 50 years for eligible individuals and excludes those who quit more than 15 years ago, despite evidence that lung cancer risk declines gradually after cessation and increases with aging.
Study Details
To address this limitation, the study authors analyzed longitudinal data from 86,035 current or former heavy smokers aged 50 years or older (mean age = 60.8 years) who had no prior cancer diagnosis at baseline. Participants were followed for up to 10 years, during which 2,109 lung cancers were diagnosed. Smoking cessation time was categorized into ≤ 5, 6 to 10, 11 to 15, and > 15 years, and multivariable extended Cox proportional hazards models were used to estimate 10-year lung cancer incidence while adjusting for age, sex, and pack-years smoked.
A key methodological feature of the study was the use of risk postponement periods (RPPs), which quantify how many years later a former smoker reaches the same lung cancer risk as a current smoker of the same smoking intensity. The investigators used age 50 years—the USPSTF-recommended starting age for current heavy smokers—as the reference point. They found that quitting smoking was associated with a marked delay in lung cancer risk. For example, individuals who quit within the past 5 years had an RPP of 2.7 years, whereas those who quit more than 15 years earlier had an RPP of 17.1 years. These estimates translated into risk-adapted screening starting ages ranging from approximately 53 years for recent quitters to 67 years for long-term quitters. As the authors noted, “former heavy smokers could be screened between 3 and 17 years later than current heavy smokers, depending on the length of smoking cessation, in order to more closely reflect their risk levels.”
Key Takeaways
The results of the study challenge the rigid 15-year quit-time cutoff currently used to exclude long-term former smokers from screening, showing that some individuals who quit more than 15 years ago may still reach clinically relevant risk levels later in life. The data also suggest that initiating screening at age 50 for all former heavy smokers may lead to unnecessary harms, such as false-positive findings, overdiagnosis, and overtreatment, particularly among those with longer cessation histories whose risk remains relatively low at younger ages. By contrast, delaying screening until a patient’s risk meaningfully increases could improve the balance of benefits and harms and potentially enhance cost-effectiveness.
These findings underscore the importance of considering both smoking history and time since cessation when deciding on starting ages for lung cancer screening. The authors argue that differentiated starting ages could both expand access to high-risk long-term quitters and reduce unnecessary screening among lower-risk individuals, offering a practical step toward more personalized lung cancer prevention strategies.
Disclosure: For full disclosures of all study authors, visit jamanetwork.com.
