Prevalence, Co-occurrence, and Prognostic Implications of S Modifiers in the Korean National Lung Cancer Screening Program.
Journal
Radiology
Journal Volume
318
Journal Issue
1
Start Page
e251656
ISSN
1527-1315
Date Issued
2026-01
Author(s)
Kim, Hyungjin
Jo, Eunseo
Kim, Jinseob
Yoon, Soon Ho
Hwang, Eui Jin
Choi, Hyewon
Jin, Kwang Nam
Lee, Kyung Hee
Kim, Hyae Young
Goo, Jin Mo
Abstract
Background The documentation of clinically significant incidental findings (S modifiers) in low-dose CT lung cancer screening varies among radiologists. Although the Korean National Lung Cancer Screening Program adopted structured reporting for seven standardized S modifiers, the prognostic value of standardized S modifiers has not been evaluated comprehensively. Purpose To evaluate the implementation of structured reporting for prespecified S modifiers by analyzing their prevalence, mortality associations, and co-occurrence patterns. Materials and Methods This retrospective study included baseline screening participants from the Korean National Lung Cancer Screening Program between August 2019 and December 2020. The prevalence of seven S modifiers was calculated, and their prognostic value for all-cause mortality was assessed using multivariable Cox regression. Latent class analysis (LCA) was performed to identify co-occurrence patterns, which were analyzed for mortality risk stratification. Results Among 125 600 participants (mean age ± SD, 62 years ± 5.3; 123 331 men), 2.69% ( = 3380) died over a median follow-up of 3.7 years. Coronary artery calcification was most prevalent (15.07% [18 892 of 125 366 participants]), followed by emphysema (13.77% [17 300 of 125 600 participants]), interstitial lung abnormalities (ILAs) (2.65% [3324 of 125 600 participants]), and pulmonary infection (0.90% [1123 of 124 477 participants]). Extrapulmonary malignancy (74 of 125 257 participants), aortic aneurysm (78 of 125 256 participants), and pleural and/or pericardial effusion (75 of 125 253 participants) were each observed in less than 0.1% of participants. All S modifiers were associated with increased all-cause mortality, with adjusted hazard ratios (HRs) of 8.28 (95% CI: 5.48, 12.51) for pleural and/or pericardial effusion, 3.58 (95% CI: 1.97, 6.49) for extrapulmonary malignancy, 3.28 (95% CI: 1.71, 6.32) for aortic aneurysm, 2.16 (95% CI: 1.89, 2.47) for ILAs, 1.41 (95% CI: 1.30, 1.53) for coronary artery calcification, and 1.15 (95% CI: 1.05, 1.25) for emphysema ( < .001 for all except for emphysema, with = .002). LCA helped identify four distinct classes with a stepwise increase in mortality from isolated emphysema (adjusted HR, 1.22; 95% CI: 1.10, 1.36; < .001) to high-risk modifiers (adjusted HR, 5.35; 95% CI: 3.40, 8.41; < .001). Conclusion In a nationwide lung cancer screening group, structured reporting using seven standardized S modifiers revealed both their prevalence and associations with all-cause mortality, validating their clinical utility in identifying clinically significant abnormalities. © RSNA, 2026 See also the editorial by White and Gierada in this issue.
Type
journal article