“…The present study analyzed the following variables: - Patient characteristics including age, sex, body mass index, smoking history (yes or on), chronic interstitial or obstructive lung disease (yes or no), family history of lung cancer (yes or no), and history of extra-thoracic malignant neoplasm (>5 years ago, yes or no).
- Image-based features consisted of emphysema (yes or no) and nodule parameters including diameter, upper lobe location (yes or no), marginal spiculation (yes or no), significant lung nodule enhancement (yes [>15 HU] or no [≤15 HU]), and pleural indentation (yes or no) based on previous studies 5,13,15
- Tumor biomarkers including carcinoembryonic antigen (CEA, normal [≤5.0 μg/L] or abnormal [>5.0 μg/L]), carbohydrate antigen 125 (normal [≤35.0 kU/L] or abnormal [>35.0 kU/L]), carbohydrate antigen 199 (normal [≤27.0 kU/L] or abnormal [>27.0 kU/L]), carbohydrate antigen 724 (normal [≤6.9 kU/L] or abnormal [>6.9 kU/L]), neuron-specific enolase (normal [≤16.3 μg/L] or abnormal [>16.3 μg/L]), squamous cell carcinoma antigen (normal [≤1.5 μg/L] or abnormal [>1.5 μg/L]), and ferritin (normal [13–150 μg/L] or abnormal [<13 or >150 μg/L]).
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