Background The optimal screening policy for lung cancer is unknown. Objective To identify efficient CT-screening scenarios where relatively more lung cancer deaths are averted for fewer CT screens. Design Comparative modeling study using 5 independent models. Data Sources The National Lung Screening Trial, the Prostate, Lung, Colorectal and Ovarian trial, the Surveillance, Epidemiology, and End Results program, and U.S. Smoking History Generator. Target Population U.S. cohort born in 1950. Time Horizon Cohort followed from ages 45 to 90. Perspective Societal. Intervention 576 scenarios with varying eligibility criteria (age, smoking pack-years, years quit) and screening intervals. Outcome Measures Benefits: lung cancer deaths averted or life-years gained; harms: CT-exams, false positives (including biopsy/surgery), overdiagnosed cases, radiation-related deaths. Results of Best-Case Annual screening from age 55 through 80 for ever-smokers with at least 30 pack-years and ex-smokers with less than 15 years since quitting was the most advantageous strategy. It would lead to 50% (45 to 54%) of cancers being detected at an early stage (I/II); 575 screens per lung cancer death averted; a 14% (8.2 to 23.5%) lung cancer mortality reduction; 497 lung cancer deaths averted; and 5,250 life-years gained per the 100,000-member cohort. Harms would include 67,550 false-positive tests, 910 biopsies or surgeries for benign lesions and 190 overdiagnosed cancers (3.7%; 1.4 to 8.3%). Results of Sensitivity Analysis The number of cancer deaths averted for the scenario varied across models between 177 and 862, and for overdiagnosed cancers between 72 and 426. Limitations Scenarios assumed 100% screening adherence. Data derived from trials with short duration were extrapolated to life-time follow-up. Conclusion Annual CT screening for lung cancer has a favorable benefit-harm ratio for individuals aged 55 through 80 years with 30 or more pack-year exposure to smoking.

BackgroundConsiderable effort has been expended on tobacco control strategies in the United States since the mid-1950s. However, we have little quantitative information on how changes in smoking behaviors have impacted lung cancer mortality. We quantified the cumulative impact of changes in smoking behaviors that started in the mid-1950s on lung cancer mortality in the United States over the period 1975–2000.MethodsA consortium of six groups of investigators used common inputs consisting of simulated cohort-wise smoking histories for the birth cohorts of 1890 through 1970 and independent models to estimate the number of US lung cancer deaths averted during 1975–2000 as a result of changes in smoking behavior that began in the mid-1950s. We also estimated the number of deaths that could have been averted had tobacco control been completely effective in eliminating smoking after the Surgeon General’s first report on Smoking and Health in 1964.ResultsApproximately 795 851 US lung cancer deaths were averted during the period 1975–2000: 552 574 among men and 243 277 among women. In the year 2000 alone, approximately 70 218 lung cancer deaths were averted: 44 135 among men and 26 083 among women. However, these numbers are estimated to represent approximately 32% of lung cancer deaths that could have potentially been averted during the period 1975–2000, 38% of the lung cancer deaths that could have been averted in 1991–2000, and 44% of lung cancer deaths that could have been averted in 2000.ConclusionsOur results reflect the cumulative impact of changes in smoking behavior since the 1950s. Despite a large impact of changing smoking behaviors on lung cancer deaths, lung cancer remains a major public health problem. Continued efforts at tobacco control are critical to further reduce the burden of this disease.