Background: The US Preventive Services Task Force (USPSTF) recommends lung cancer screening for individuals aged 50 to 80 years with a smoking history of at least 20 pack-years and no more than 15 quit-years. This approach implies that former heavy smokers with at least 20 pack-years would either be offered screening from 50 years of age onward or not at all, depending on a dichotomous classification by time since smoking cessation. Alternatively, screening strategies could be better aligned with the individual risk profiles of former smokers.
Objectives:  To develop a more personalized lung cancer screening strategy that reflects individual risks by defining risk-adapted starting ages for screening according to time since cessation.
Methods: The association between smoking cessation time, pack-years, age, and 10-year lung cancer incidence was assessed using multivariable extended Cox proportional hazards models. Risk postponement periods (RPPs) were estimated from the regression coefficients for time since cessation and age. These RPP estimates were used to derive risk-adapted starting ages for lung cancer screening among former heavy smokers, using the USPSTF-proposed starting age of 50 years as a reference for the risk level of continuing heavy smokers.
Results: A total of 86?035 former or current heavy smokers were included in the analysis, of whom 2109 (2.5%) were diagnosed with lung cancer during follow-up. The RPPs for smoking cessation were 2.7 (95% CI, 0.0-5.3), 6.2 (95% CI, 4.4-7.9), 10.4 (95% CI, 8.5-12.4), and 17.1 (95% CI, 15.0-19.2) years for former heavy smokers who quit at least 5, 6 to 10, 11 to 15, and more than 15 years ago, respectively. This could translate to risk-adapted screening starting ages ranging from 53 (95% CI, 50-55) years to 67 (95% CI, 65-69) years, if current smokers begin screening at age 50.
Conclusions/Implications: This cohort study using UK Biobank data provides an empirical basis for risk-adapted starting ages for lung cancer screening among former heavy smokers. Incorporating time since smoking cessation into screening initiation may allow later screening for some low-risk individuals while enabling the inclusion of high-risk long-term former smokers, improving the overall balance of benefits and harms of lung cancer screening.
This abstract is based on previously published work in JAMA Network Open:
Frick C, Hallsson LR, Siebert U, Bhardwaj M, Schöttker B, Brenner H. Risk-Adapted Lung Cancer Screening Starting Ages for Former Smokers. JAMA Netw Open. 2025;8(12):e2551281. doi:10.1001/jamanetworkopen.2025.51281.