Structured triage of incidental findings in lung cancer screening: Outcomes from a UK programme.

Background

Low-dose CT (LDCT) lung cancer screening frequently identifies incidental findings (IFs). These have the potential to be beneficial or harmful to the participant and need to be managed effectively. We evaluated whether structured triage of IFs in a real-world screening programme led to meaningful clinical actions or benefit.

Methods

We retrospectively reviewed IFs referred according to the national protocol between January 2023 and May 2025. Outcomes included no further action, investigation, referral, surveillance, and/or treatment. Additional detailed analysis evaluated management and early outcomes of moderate or severe coronary artery calcification (CAC).

Results

Of 15,465 LDCT scans, 1,049 IFs in 1,030 participants were referred and reviewed by the service (6.8% of total LDCTs). Thirty-seven percent required no action after review; 23% required a single investigation. 292 (27.8%) led to new diagnoses; 51 participants (4.9%) received medical treatment, and 15 (1.4%) underwent surgery. Sixty-three incidental cancers were detected, of which 63.5% received radical treatment. Common IFs included aortic valve calcification (21.0%), thoracic aortic dilatation (10.0%), and renal abnormalities (9.9%). Among 904 participants with moderate or severe CAC, 220 were not on lipid-lowering therapy at baseline. Of these, only 35% initiated treatment within two years. All-cause mortality in this group was 4.7% at two years, with one-third due to cardiovascular causes.

Conclusion

Structured triage enables consistent, proportionate IF management. Most IFs required no ongoing follow-up, while a minority led to diagnosis and intervention. CAC was common and undertreated, highlighting a modifiable competing risk that should be integrated into lung cancer screening pathways.