Practical Strategy to Mitigate Overdiagnosis in Asian Low-dose Computed Tomography Lung Cancer Screening

Low-dose computed tomography (LDCT) screening reduces lung cancer mortality but may lead to overdiagnosis and overtreatment, especially among the Asian LDCT screening population presenting with subsolid nodules (SSNs). Thus, we explored whether implementing chest X-ray (CXR) triage as a preliminary screening tool can improve patient selection and reduce unnecessary interventions.

This retrospective cohort study compared patients who underwent direct LDCT screening with those who underwent LDCT and CXR triage. Medical records of 506 patients with SSNs ≤3cm from January 2006 to December 2021 were reviewed. Primary outcomes included lung cancer prognosis, relapse, and histopathologic spectrum of lung adenocarcinoma to assess potential overdiagnosis. The CXR triage group consisted of patients who had both LDCT and CXR within 3 months, with CXR-visible nodules confirmed by surgical pathology. A 1:1 propensity score matching (PSM) was performed using age, sex, and nodule size, resulting in 97 matched pairs for balanced outcome comparison.

After PSM, 194 patients were analyzed. In the direct LDCT group, 37.1% of resected lesions were adenocarcinoma in situ (AIS) or atypical adenomatous hyperplasia (AAH), indicating a higher likelihood of overdiagnosis. Conversely, the CXR triage group had no patients with AIS/AAH, a significant difference. No significant differences were observed in disease-free survival or relapse rates between groups during follow-up, suggesting that CXR triage may reduce overtreatment without negatively impacting short-term prognosis. Multivariate Cox regression revealed that age, sex, nodule size, smoking status, and screening method were not significant predictors of mortality. Kaplan-Meier survival analysis over 15 years showed similarly high survival rates in both groups, with no significant difference.

CXR triage is a preliminary step in LDCT screening for lung cancer, particularly in non-smoking Asian high-risk populations, to reduce unnecessary surgical procedures while preserving diagnostic effectiveness. Further prospective multicenter studies are needed to validate its long-term safety, cost-effectiveness, and acceptability in routine clinical practice.