Nomograms Using CT Morphological Features and Clinical Characteristics to Identify COPD in Patients with Lung Cancer: A Multicenter Study

Wenting Tu,1,* Taohu Zhou,1,2,* Xiuxiu Zhou,1,* Yanqing Ma,3 Shaofeng Duan,4 Yun Wang,1 Xiang Wang,1 Tian Liu,1 HanXiao Zhang,5 Yan Feng,1 Wenjun Huang,2 Xinang Jiang,1 Yi Xiao,1 Shiyuan Liu,1 Li Fan1 1Department of Radiology, Second Affiliated Hospital of Naval Medical University, Shanghai, 200003, People’s Republic of China; 2School of Medical Imaging, Weifang Medical University, Weifang, Shandong, 261053, People’s Republic of China; 3Department of Radiology, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital of Hangzhou Medical College, Hangzhou, Zhejiang, 310000, People’s Republic of China; 4GE Healthcare, Precision Health Institution, Shanghai, 210000, People’s Republic of China; 5School of Medical Imaging, Xuzhou Medical University, Xuzhou, Jiangsu, 221018, People’s Republic of China*These authors contributed equally to this workCorrespondence: Shiyuan Liu; Li Fan, Department of Radiology, Second Affiliated Hospital, Naval Medical University, No. 415 Fengyang Road, Shanghai, 200003, People’s Republic of China, Tel +86 21 81886012 ; +86 21 81886018, Fax +86 21 63587668, Email cjr.liushiyuan@vip.163.com; fanli0930@163.comPurpose: This study aimed to screen out computed tomography (CT) morphological features and clinical characteristics of patients with lung cancer to identify chronic obstructive pulmonary disease (COPD). Further, we aimed to develop and validate different diagnostic nomograms for predicting whether lung cancer is comorbid with COPD.Patients and Methods: This retrospective study examined data from 498 patients with lung cancer (280 with COPD, 218 without COPD; 349 in training cohort, 149 in validation cohort) from two centers. Five clinical characteristics and 20 CT morphological features were evaluated. Differences in all variables were assessed between COPD and non-COPD groups. Models were developed using multivariable logistic regression to identify COPD, including clinical, imaging, and combined nomograms. Receiver operating characteristic curves were used to evaluate and compare the performance of nomograms.Results: Age, sex, interface, bronchus cutoff sign, spine-like process, and spiculation sign were independent predictors of COPD in patients with lung cancer. In the training and validation cohorts, the clinical nomogram showed good performance to predict COPD in lung cancer patients (areas under the curves [AUCs] of 0.807 [95% CI, 0.761– 0.854] and 0.753 [95% CI, 0.674– 0.832]); while the imaging nomogram showed slightly better performance (AUCs of 0.814 [95% CI, 0.770– 0.858] and 0.780 [95% CI, 0.705– 0.856]). For the combined nomogram generated with clinical and imaging features, the performance was further improved (AUC=0.863 [95% CI, 0.824– 0.903], 0.811 [95% CI, 0.742– 0.880] in the training and validation cohort). At 60% risk threshold, there were more true negative predictions (48 vs 44) and higher accuracy (73.15% vs 71.14%) for the combined nomogram compared with the clinical nomogram in the validation cohort.Conclusion: The combined nomogram developed with clinical and imaging features outperformed clinical and imaging nomograms; this provides a convenient method to detect COPD in patients with lung cancer using one-stop CT scanning.Keywords: chronic obstructive pulmonary disease, lung cancer, computed tomography, chest imaging, nomogram