Stage shifts in national lung adenocarcinoma and the impact of opportunistic self-initiated LDCT screening in Taiwan

Background: Lung cancer in Taiwan is never-smoking and adenocarcinoma (LUAD) predominant. This study evaluated national LUAD stage-shifts and their association with opportunistic, self-initiated low-dose computed tomography (LDCT) screening. Methods: A retrospective study was conducted using Taiwan Cancer Registry (TCR) data (2011–2023), and self-initiated LDCT screening records from five medical centers (2011–2021). Patients were classified as early-stage (stage I) and late-stage (stage II–IV). Outcomes included age-standardized incidence rate (ASIR), age-standardized incidence-based mortality (ASIBM), and average annual percentage change (AAPC) of national LUAD, and screening volume of self-initiated LDCT. Findings: Among 126,753 LUAD cases 71,159 (56.1%) were females and 87,830 (69.3%) never smoked. The opportunistic self-initiated LDCT screening revealed 70,803 individuals, most never smoked (83.7%) and were male (56.6%). ASIRs of stage 0 (AAPC, 49.6%; 95% confidence interval [CI], 43.3–71.0) and early-stage (AAPC, 13.0%; 95% CI, 12.3–13.7) increased significantly. Conversely, late-stage ASIRs declined in selected subgroups, including never-smoking females aged <55 years (AAPC, −1.9%; 95% CI, −0.3 to −0.9) and in smoking patients aged ≥75 years (males AAPC, −2.3%; 95% CI, −3.1 to −1.5; females AAPC, −3.9%; 95% CI, −6.3 to −1.3). Rising LDCT screening volume descriptively paralleled this stage-shift in never-smoking females. ASIBM declined significantly over time, particularly in advanced-stage disease. Interpretation: The coexistence of increasing early-stage incidence, largely stable late-stage disease, and declining incidence-based mortality suggests a transition phase characterized by both detection expansion and emerging clinical benefit. The increase in self-initiated LDCT screenings paralleled the stage-shift among never-smoking females, and further research is needed to assess long-term outcomes and cost-effectiveness. Funding: Health Promotion Administration, Ministry of Health and Welfare; the Ministry of Health and Welfare and Formatting the Risk Prediction Models for Never-Smoking Lung Cancer (FORMOSA).