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Abstract Background With the increasing prevalence of nonsmoking-related lung cancer in Asia, Asian countries have increasingly adopted low-dose computed tomography (LDCT) for lung cancer screening, particularly in private screening programs. This study examined how annual LDCT volume affects lung cancer stage distribution, overdiagnosis, and gender disparities using a hospital-based lung cancer database. Methods This study analyzed the annual utilized LDCT volume, clinical characteristics of lung cancer, stage shift distribution, and potential overdiagnosis. At the individual level, this study also investigated the relationship between stage 0 lung cancer (potential strict definition regarding overdiagnosis) and the clinical characteristics of lung cancer. Results This study reviewed the annual trend of 4971 confirmed lung cancer cases from 2008 to 2021 and conducted a link analysis with an LDCT imaging examination database over these years. As the volume of lung cancer screenings has increased over the years, the number and proportion of stage 0 lung cancers have increased proportionally. Our study revealed that the incidence of stage 0 lung cancer increased with increasing LDCT scan volume, particularly during the peak growth period from 2017 to 2020. Conversely, stage 4 lung cancer cases remained consistent across different time intervals. Furthermore, the increase in the lung cancer screening volume had a more pronounced effect on the increase in stage 0 lung cancer cases among females than it had among males. The estimated potential for overdiagnosis brought about by the screening process, compared to non-participating individuals, ranged from an odds ratio of 7.617 to one of 17.114. Both strict and lenient definitions of overdiagnosis (evaluating cases of stage 0 lung cancer and stages 0 to 1 lung cancer) were employed. Conclusions These results provide population-level evidence of potential lung cancer overdiagnosis in the Taiwanese population due to the growing use of LDCT screening, particularly concerning the strict definition of stage 0 lung cancer. The impact was greater in the female population than in the male population, especially among females younger than 40 years. To improve lung cancer screening in Asian populations, creating risk-based prediction models for smokers and nonsmokers, along with gender-specific strategies, is vital for ensuring survival benefits and minimizing overdiagnosis.

Lung cancer (LC) stands as the foremost cause of cancer-related fatality rates worldwide. Early diagnosis significantly enhances patient survival rate. Nowadays, low-dose computed tomography (LDCT) is widely employed on the chest as a tool for large-scale lung cancer screening. Nonetheless, a large amount of chest radiographs creates an onerous burden for radiologists. Some computer-aided diagnostic (CAD) tools can provide insight to the use of medical images for diagnosis and can augment diagnostic speed. However, due to the variation in the parameter settings across different patients, substantial discrepancies in image voxels persist. We found that different voxel sizes can create a compromise between model generalization and diagnostic efficacy. This study investigates the performance disparities of diagnostic models trained on original images and LDCT images reconstructed to different voxel sizes while making isotropic. We examined the ability of our method to differentiate between benign and malignant nodules. Using 11 features, a support vector machine (SVM) was trained on LDCT images using an isotropic voxel with a side length of 1.5 mm for 225 patients in-house. The result yields a favorable model performance with an accuracy of 0.9596 and an area under the receiver operating characteristic curve (ROC/AUC) of 0.9855. In addition, to furnish CAD tools for clinical application, future research including LDCT images from multi-centers is encouraged. [ABSTRACT FROM AUTHOR]

Background: Previous studies have shown that excessive abdominal visceral adipose tissue (AVAT) and epicardial adipose tissue (EAT) are risk factors of cardiometabolic disease; we hypothesized there is differential contribution of abdominal and cardiac fat deposits to the cardiometabolic profiles.Methods: Two hundred eight consecutive subjects with clinical suspicion of coronary artery disease (CAD) who underwent cardiac and abdominal CT for Agatston score and abdominal visceral fat measurement were retrospectively analyzed. Regional thickness of EAT (EATth), total volume of EAT, total volume of paracardial adipose tissue (PAT) and total volume of AVAT from L2 to L5 level were measured. The relationships between abdominal and cardiac adipose tissue measurements, the number of components of metabolic syndrome, and the severity of Agatston score on a four ranking scale (0, 1-10,11-100, 101-400, >400) were investigated.Results: The amounts of AVAT, EAT, PAT and EATth-LAVG showed a significant linear trend with increasing number (0-5) of components in metabolic syndrome (AVAT, EAT and PAT P for trend <0.0001; EATth-LVAG P for trend <0.001). EATth at left atrioventricular groove (EATth-LAVG) showed significant linear trend with the severity of Agatston score on a four ranking scale (P for trend <0.0001). In multivariate binary regression analysis, total volume of AVAT was the sole adiposity predictor for metabolic syndrome independent to age, gender, and waist circumference (odds ratio of 1.20, 95 % CI 1.08-1.32, p < 0.001) while total volume of EAT, PAT, and EATth-LAVG were not. In contrary, EATth-LAVG was the sole adiposity predictor for Agatston score >400 (odds ratio of 1.11, 95% CI 1.034-1.184, p = 0.004).Conclusions: Excessive total volume of AVAT appears to be preferentially associated with metabolic syndrome; while EAT, esp. EATth-LAVG is preferentially associated with coronary artery disease. This differential effect of the two adiposities deserves a large-scale cohort study for further investigation. [ABSTRACT FROM AUTHOR]

Background: Numerous studies have validated a 5-year warranty period for heart health in Western populations with a coronary artery calcium (CAC) score of zero. While the calcium score is a crucial cardiovascular risk indicator, its interpretation in Asian populations remains unclear. This meta-analysis aimed to clarify the uncertainty surrounding the prevalence, warranty period, and prognostic implications of zero CAC scores in Asian populations. It also examined the impact of sex on subclinical CAC progression. While the calcium score is a crucial cardiovascular risk indicator, its interpretation in Asian populations remains unclear. The study aimed to shed light on these issues by exploring the specificities of subclinical CAC progression in the Asian context., Methods: Our systematic literature search, from the study's inception to October 2023, targeted studies on subclinical CAC progression in the Asian population with a zero CAC score. We searched the Cochrane Library, and PubMed. The search terms included "zero score", "coronary calcification", "zero CAC score", and "CAC scan"., Results: We evaluated seven published studies through a meta-analysis and assessed the risk of bias using the Newcastle-Ottawa Scale (NOS). In this meta-analysis of three observational studies addressing zero CAC prevalence (n=7,661), the pooled prevalence of zero CAC scores in the Asian population was 18.2% [95% confidence interval (CI): 12.5-25.9%]. A significant difference in follow-up warranty period was observed between the CAC zero group and subclinical CAC progression group (mean difference, 1.26 years; 95% CI: 0.94-1.58; P<0.001). Furthermore, the conversion rate of subclinical CAC progression differed significantly between males and females (risk ratio, 2.37; 95% CI: 1.98-2.84; P<0.001). Analysis of four studies revealed a notable discrepancy in the major adverse cardiovascular event (MACE) rate between the CAC (-) and CAC (+) groups (risk ratio, 4.78; 95% CI: 2.21-10.36; P<0.001)., Conclusions: The meta-analysis of zero CAC scores in Asian populations suggested an 18.2% prevalence. A 5-year warranty period was noted, with heightened subclinical CAC progression likelihood after this duration. Additionally, sex-based differences were observed in subclinical CAC progression rates. These findings will provide clinical cardiovascular risk stratification for guiding gender-specific clinical decision-making in asymptomatic in Asian individuals., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://cdt.amegroups.com/article/view/10.21037/cdt-23-474/coif). The authors have no conflicts of interest to declare., (2024 Cardiovascular Diagnosis and Therapy. All rights reserved.)