Changes in Uptake, Participant Disparities, and Screening Outcomes of the Korean National Lung Cancer Screening...

Low-dose computed tomography (LDCT) is effective in reducing lung cancer mortality among high-risk smokers. The Korean National Lung Cancer Screening Program (KNLCS), the world's first nationwide lung cancer screening initiative using LDCT, was launched in 2019. This study aimed to evaluate the KNLCS uptake rates in relation to participants' economic status and changes in positive screening rates across screening rounds.

Data from the National Health Insurance Service (NHIS) and National Cancer Screening Information System for 2019-2023 were analyzed. Eligible participants in the KNLCS were current smokers aged 54-74 years with a smoking history of at least 30 pack-years. The KNLCS provides counseling by physicians on screening results and smoking cessation. Screening uptake rates, counseling rates, and Lung CT Screening Reporting and Data System (Lung-RADS) distributions were assessed.

Screening uptake rates increased from 24.7% in 2019 to 51.2% in 2023 (p < 0.001). Economic disparities were observed, with higher-income groups showing consistently higher uptake rates than lower-income group. Screening positive rates has been decreased from 9.1% in 2019 to 7.0% in 2023 according to increasing the proportion of subsequent screening participants. The inter-institutional variance in Lung-RADS category 4 decreased significantly over the years (p < 0.001).

The KNLCS rapidly increased screening uptake rates by systematically inviting eligible participants. Positive screening rates decreased primarily due to a reduction in Lung-RADS category 3 findings in subsequent rounds.