Association of baseline screening results and management with subsequent adherence in the Korean national lung cancer screening program.

[BACKGROUND] Adherence to subsequent lung cancer screening (LCS) is essential but not well characterized in biennial national programs.

[OBJECTIVES] To assess whether baseline LCS results and their management are associated with subsequent screening adherence and clinical outcomes.

[METHODS] We analyzed participants in the Korean national LCS program who underwent baseline low-dose computed tomography (CT) between 2019 and 2021 and remained lung cancer-free for 2 years. Baseline results were classified as true negative or false positive (FP); FPs were grouped by management (invasive diagnostic procedures, chest CT surveillance, or no further evaluation). Adherence to the next biennial screening was modeled using multivariable logistic regression. Lung cancer incidence and all-cause mortality were assessed using Cox models with a 2-year landmark design.

[RESULTS] Among 235,753 participants, 54.4% returned for subsequent screening. Compared with true-negative results, adherence was lower among those with FP results who underwent invasive procedures (adjusted odds ratio [aOR], 0.64; 95% confidence interval [CI], 0.56-0.72) or CT surveillance (aOR, 0.77; 95% CI, 0.74-0.80) but was similar among those with FP results without further evaluation (aOR, 1.00; 95% CI, 0.95-1.04). In the landmark analysis, FPs were associated with higher risks of lung cancer incidence (adjusted hazard ratios [aHRs], 2.95-2.49 across management groups) and higher all-cause mortality among those who underwent invasive procedures (aHR, 1.57; 95% CI, 1.10-2.24) or CT surveillance (aHR, 1.23; 95% CI, 1.07-1.41).

[CONCLUSION] Downstream management after baseline FP findings, rather than FP status alone, was associated with subsequent LCS adherence, highlighting the need to support return screening in higher risk FP groups.