title: Preoperative nomogram for identifying invasive pulmonary adenocarcinoma in patients with pure ground-glass nodule: A multi-institutional study.
abstract: OBJECTIVE
  To construct a preoperative nomogram to differentiate invasive pulmonary adenocarcinomas (IPAs) from preinvasive lesions in patients with solitary pure ground-glass nodules (GGN).
  
  
  METHODS
  A primary cohort of patients with pathologically confirmed pulmonary solitary pure GGN after surgery were retrospectively studied at five institutions from January 2009 to September 2015. Half of the patients were randomly selected and assigned to a model-development cohort, and the remaining patients were assigned to a validation cohort. A nomogram predicting the invasive extent of the solitary GGNs was constructed based on the independent risk factors. Predictive performance was evaluated by concordance index (C-index) and calibration curve.
  
  
  RESULTS
  Out of 898 cases included in the study, 501 (55.8%) were preinvasive lesions and 397 (44.2%) were IPAs. In the univariate analysis, lesion size (p < 0.001), lesion margin (p = 0.041), lesion shape (p < 0.001), mean computed tomography (CT) value (p = 0.018), presence of pleural indentation (p = 0.017), and smoking status (p = 0.014) were significantly associated with invasive extent. In multivariate analysis, lesion size (p < 0.001), lesion margin (p = 0.042), lesion shape (p < 0.001), mean CT value (p = 0.014), presence of pleural indentation (p = 0.026), and smoking status (p = 0.004) remained the predictive factors of invasive extent. A nomogram was developed and validation results showed a C-index of 0.94, demonstrating excellent concordance between predicted and observed results.
  
  
  CONCLUSIONS
  We established and validated a novel nomogram that can identify IPAs from preinvasive lesions in patients with solitary pure GGN.
authors.affiliation: Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, P.R. China.
authors.forename: Yunlang
authors.initials: Y
authors.lastname: She
authors.affiliation: Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, P.R. China.
authors.forename: Lilan
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, P.R. China.
authors.forename: Chenyang
authors.initials: C
authors.lastname: Dai
authors.affiliation: Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, P.R. China.
authors.forename: Yijiu
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, P.R. China.
authors.forename: Junyan
authors.initials: J
authors.lastname: Zha
authors.affiliation: Department of Pathology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, P.R. China.
authors.forename: Huikang
authors.initials: H
authors.lastname: Xie
authors.affiliation: Department of Radiology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, P.R. China.
authors.forename: Sen
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Department of Radiology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, P.R. China.
authors.forename: Jingyun
authors.initials: J
authors.lastname: Shi
authors.affiliation: Department of Thoracic Surgery, The Affiliated Wujiang Hospital of Nantong University, Jiangsu, P.R. China.
authors.forename: Shunbin
authors.initials: S
authors.lastname: Shi
authors.affiliation: Department of Thoracic Surgery, Nantong Sixth People's Hospital, Jiangsu, P.R. China.
authors.forename: Weirong
authors.initials: W
authors.lastname: Shi
authors.affiliation: Department of Thoracic Surgery, Fenghua People's Hospital, Zhejiang, P.R. China.
authors.forename: Bing
authors.initials: B
authors.lastname: Yu
authors.affiliation: Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, P.R. China.
authors.forename: Gening
authors.initials: G
authors.lastname: Jiang
authors.affiliation: Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, P.R. China.
authors.forename: Ke
authors.initials: K
authors.lastname: Fei
authors.affiliation: Department of Thoracic Surgery, The Second Affiliated Hospital of Soochow University, Jiangsu, P.R. China.
authors.forename: Yongbing
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, P.R. China.
authors.forename: Chang
authors.initials: C
authors.lastname: Chen
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D016015:Logistic Models; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D049451:Nomograms; D057234:Preoperative Period; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: ground-glass nodule; lung adenocarcinoma; nomogram