Long-term efficacy and adherence of a lung cancer screening strategy with extended LDCT intervals: Results from the BioMILD trial.

Lung cancer (LC) screening with low-dose computed tomography (LDCT) reduces mortality through early-stage detection, yet evidence on long-term effectiveness and adherence remains limited. This study reports nearly 10-year outcomes from the prospective BioMILD trial, which enrolled 4,119 heavy smokers undergoing risk-adapted screening with LDCT. Participants were stratified by baseline LDCT results into LDCT + and LDCT - groups, and the latter were sent to triennial intervals. Over a median follow-up of 9.4 years (38,676 person-years), 248 LCs were diagnosed (6.0 %), with significantly higher incidence in the LDCT + group (21.8 % vs 3.0 %, p < 0.0001). Early-stage disease predominated across all four screening intervals (0-2, 3-5, 6-9, and ≥ 9 years), with stage I proportions consistently around or above 50 %. Ten-year all-cause and LC mortality were significantly higher in the LDCT + group (14 % and 5 %) compared to the LDCT - group (6 % and 1 %) (p < 0.0001). Screening adherence remained high at 3-5 years (92 %) and acceptable beyond 9 years (58 %), with no group differences. Baseline LDCT effectively stratified long-term risk, with over seven-fold higher LC incidence in LDCT + participants. However, LC cases continued to emerge in the LDCT - group, indicating that a negative baseline LDCT does not eliminate long-term risk. Despite differing risk profiles, screening maintained a consistent ability to detect early-stage LC across groups. In conclusion, long-term risk-adapted LDCT screening in the BioMILD trial sustained early-stage LC detection and acceptable adherence over nearly a decade, supporting continued surveillance even among initially low-risk individuals.