title: Analysis of the discriminative methods for diagnosis of benign and malignant solitary pulmonary nodules based on serum markers.
abstract: BACKGROUND
  Screening indexes of tumor serum markers for benign and malignant solitary pulmonary nodules (SPNs) were analyzed to find the optimum method for diagnosis.
  
  
  METHODS
  Enzyme-linked immunosorbent assays, an automatic immune analyzer and radioimmunoassay methods were used to examine the levels of 8 serum markers in 164 SPN patients, and the sensitivity for differential diagnosis of malignant or benign SPN was compared for detection using a single plasma marker or a combination of markers. The results for serological indicators that closely relate to benign and malignant SPNs were screened using the Fisher discriminant analysis and a non-conditional logistic regression analysis method, respectively. The results were then verified by the k-means clustering analysis method.
  
  
  RESULTS
  The sensitivity when using a combination of serum markers to detect SPN was higher than that using a single marker. By Fisher discriminant analysis, cytokeratin 19 fragments (CYFRA21-1), carbohydrate antigen 125 (CA125), squamous cell carcinoma antigen (SCC) and breast cancer antigen (CA153), which relate to the benign and malignant SPNs, were screened. Through non-conditional logistic regression analysis, CYFRA21-1, SCC and CA153 were obtained. Using the k-means clustering analysis, the cophenetic correlation coefficient (0.940) obtained by the Fisher discriminant analysis was higher than that obtained with logistic regression analysis (0.875).
  
  
  CONCLUSIONS
  This study indicated that the Fisher discriminant analysis functioned better in screening out serum markers to recognize the benign and malignant SPN. The combined detection of CYFRA21-1, CA125, SCC and CA153 is an effective way to distinguish benign and malignant SPN, and will find an important clinical application in the early diagnosis of SPN.
authors.affiliation: Department of Oncology, People's Hospital of Henan, Zhengzhou, China.
authors.forename: Wanping
authors.initials: W
authors.lastname: Wang
authors.forename: Mingyue
authors.initials: M
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Rui
authors.initials: R
authors.lastname: Tian
authors.forename: Junqiang
authors.initials: J
authors.lastname: Dong
authors.forename: Qi
authors.initials: Q
authors.lastname: Liu
authors.forename: Xianping
authors.initials: X
authors.lastname: Zhao
authors.forename: Yuanfang
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000951:Antigens, Neoplasm / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood*; D018394:CA-125 Antigen / Q000097:blood; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005189:False Positive Reactions; D006801:Humans; D053539:Keratin-19 / Q000097:blood; D016015:Logistic Models; D008175:Lung Neoplasms / Q000097:blood / Q000175:diagnosis*; D008565:Membrane Proteins / Q000097:blood; D018396:Mucin-1 / Q000097:blood; D011237:Predictive Value of Tests; D011863:Radioimmunoassay; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015843:Serpins / Q000097:blood; D003074:Solitary Pulmonary Nodule / Q000097:blood / Q000175:diagnosis*
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D018394:CA-125 Antigen; D053539:Keratin-19; C451759:MUC16 protein, human; D008565:Membrane Proteins; D018396:Mucin-1; D015843:Serpins; C102012:antigen CYFRA21.1; C051072:squamous cell carcinoma-related antigen