East–West Disparities in Lung Cancer Screening: Subsolid Nodule Prevalence, Interval Growth, and Decision-Making Analysis

Lung cancer screening has been widely studied, and strong evidence supports its role in reducing mortality among heavy smokers. The 2011 National Lung Screening Trial demonstrated a 20% reduction in lung cancer mortality, with further validation from European trials, such as NELSON and MILD. In 2015, the United States Centers for Medicare & Medicaid Services approved lung cancer screening as a reimbursable service, later expanding the criteria in 2021 to include individuals aged 50–80 years with a ≥20 pack-year smoking history. While screening models such as the Prostate, Lung, Colorectal, and Ovarian (PLCO) have effectively stratified risk among smokers, emerging research on non-smokers remains inconclusive. This review highlights five key issues in lung cancer screening in Eastern and Western countries. First, the screening rates differ significantly between regions owing to variations in healthcare policies and awareness. Second, subsolid nodule (SSN) prevalence varies between Eastern and Western populations, influencing screening strategies. Third, differences in SSN growth thresholds affect clinical decision-making and patient outcomes. Fourth, there are variations in the management of SSNs, particularly in follow-up recommendations and intervention strategies. Fifth, overdiagnosis remains a critical concern, with distinct challenges in each region owing to screening frequency and healthcare infrastructure. Additionally, microsimulation models predict a decline in smoking-related lung cancer but an increase in non-smoking-related cases, emphasizing the need for tailored screening approaches. Addressing these five issues is crucial for optimizing lung cancer screening strategies and balancing early detection with the risk of overdiagnosis.