Features of low-dose CT-detected lung nodules: individuals who never smoked vs. who smoke(d) in a Chinese general population

OBJECTIVES: To evaluate and compare low-dose CT (LDCT)-defined pulmonary nodule features between individuals who never smoked and who smoke(d) in a Chinese general population. MATERIALS AND METHODS: This study included 2033 participants from the Nelcin-B3 cohort who underwent baseline LDCT. Trained radiologists reviewed each CT scan and assessed nodule CT features, including nodule density, size, location, shape, edge, attachment type, calcification and perifissural nodules (PFNs). Multilevel logistic regression (adjusted for age and sex) was performed to evaluate the relationship between nodule CT features and smoking status, accounting for nodule clustering within participants. RESULTS: lung nodule (individuals who never smoked vs. who smoke(d): 33.6% vs. 42.4%, p < 0.001), with 1267 nodules were registered. Among those with nodules, the mean number of nodules per person was 1.6 (724/444) in individuals who never smoked, and 1.8 (543/302) in individuals who smoke(d) (p = 0.02). Individuals who never smoked more often had a single nodule compared to individuals who smoke(d) (67.3% vs. 58.3%, p = 0.008). No significant differences were observed in nodule CT features (p > 0.05), including nodule size, location, and morphology, between smoking groups. CONCLUSION: In the Chinese general population, smoking status was associated with lung nodule prevalence and nodule number, but not with key nodule CT features. These findings suggest that in Asian populations, nodule characteristics may be influenced by factors beyond smoking, underscoring the need for population-specific risk stratification strategies in lung nodule assessment. KEY POINTS: Question Lung nodule risk stratification relies on their CT features, yet no Asian studies have comprehensively examined these features between individuals who never smoked and who smoke(d). Findings CT features of lung nodules (e.g., size, location, morphology) showed no significant differences between smoking groups in a Chinese general population, despite observed differences in nodule prevalence and count. Clinical relevance Relying solely on smoking history may underestimate the malignancy risk of lung nodules in Asian populations, emphasizing the need for population-specific risk stratification strategies.