Background
Korea launched the Korean National Lung Cancer Screening Program (KNLCS) using low-dose computed tomography (LDCT) in August 2019 as the world’s first nationwide, organized, population-based lung cancer screening program. The program targets high-risk smokers aged 54–74 years with a smoking history of ≥30 pack-years and provides biennial LDCT screening. Assessing participation patterns across population subgroups and evaluating the impact of screening on lung cancer incidence and mortality are critical for determining the effectiveness and equity of a national screening program.
Objectives
This study aimed to assess participation rates in the KNLCS by demographic and socioeconomic characteristics and to compare lung cancer incidence and mortality between screened and non-screened populations.
Methods
Nationwide lung cancer screening participation rates were calculated as the proportion of screening participants among eligible targets from 2019 to 2023 using National Health Insurance Service databases. Participation rates were analyzed by age group, smoking history, and income level. Lung cancer incidence and mortality were compared between screened and non-screened individuals using National Cancer Center databases linked to the national cancer registry and death records. Lung cancer incidence was defined as newly diagnosed lung cancer occurring after the screening year, and mortality was defined as death after lung cancer diagnosis.
Results
Overall participation in the KNLCS increased steadily from 24.8% in 2019 to 51.2% in 2023. Screening participation varied by age group, and income level. Participation was higher among younger individuals (<65 years) than among older individuals (≥65 years) (66.0% vs. 22.1%) and among those in higher income groups compared with lower income groups (44.6% vs. 39.8%) in 2019. These disparities persisted in 2023, with higher participation among younger individuals (58.6% vs. 29.4%) and higher income groups (54.0% vs. 41.1%). The income-related gap in screening participation widened over time.
Among eligible individuals, lung cancer incidence was similar between screened and non-screened individuals in 2019 (0.69% vs. 0.67). In contrast, by 2022, lung cancer incidence differed between the two groups, with screened individuals showing a higher incidence than non-screened individuals (0.69% vs. 0.55%). Mortality after diagnosed as lung cancer among screened individuals was substantially lower than among non-screened individuals in 2019 (41.6% vs. 66.3%), and this difference remained evident through 2022 (23.1% vs. 46.7%).
Conclusions/Implications for practice or policy
Participation in Korea’s national lung cancer screening program has increased substantially since its introduction, exceeding 50% by 2023. Screening participation differed significantly by age and socioeconomic status. Screened individuals demonstrated lower lung cancer mortality compared with non-screened individuals. These findings support the effectiveness of organized population-based lung cancer screening and highlight the need for strategies to improve equitable participation and long-term outcomes.