Population Impact of Risk-Based Lung Cancer Screening on Late-Stage Incidence in Greater Manchester.

[INTRODUCTION] Low-dose computed tomography screening reduces lung cancer mortality in clinical trials, but evidence of impact in real-world programs is lacking. Here, we evaluate the impact of screening in a socio-economically deprived area at the population level. We hypothesized that late-stage lung cancer incidence, as a surrogate for lung cancer mortality, would decrease after systematic implementation of screening in a high-risk population.

[METHODS] Late-stage lung cancer incidence among individuals aged 55 to 80 years at the time of screening invitation was compared before and after screening implementation between regions with and without implementation of community-based lung cancer screening (North & East Manchester [screening] versus four neighboring regions [no screening]). The effect of screening was estimated using difference-in-difference modeling.

[RESULTS] Late-stage lung cancer incidence decreased more steeply in the screening region, such that screening was associated with a 22% reduction in late-stage lung cancer incidence among the invited age range of 55 to 80 years (adjusted incidence rate ratio, 0.78; 95% confidence interval, 0.62-0.99; p = 0.037). Targeted low-dose computed tomography screening of 2.0% of the full North & East Manchester population (n = 4468/221,240) detected 31% of all lung cancers diagnosed since screening commenced (n = 221/722), yielding a number-needed-to-screen of 20 for each cancer detected.

[CONCLUSION] Implementation of targeted, community-based lung cancer screening in an area of high socioeconomic deprivation was associated with a significant reduction in late-stage lung cancer incidence. This provides a demonstration of screening effectiveness and public health benefit.