title: Plasma secretory phospholipase A2-IIa as a potential biomarker for lung cancer in patients with solitary pulmonary nodules.
abstract: BACKGROUND
  Five-year survival for lung cancer has remained at 16% over last several decades largely due to the fact that over 50% of patients are diagnosed with locally-advanced or metastatic disease. Diagnosis at an earlier and potentially curable stage is crucial. Solitary pulmonary nodules (SPNs) are common, but the difficulty lies in the determination of which SPN is malignant. Currently, there is no convenient and reliable biomarker effective for early diagnosis. Secretory phospholipase A2-IIa (sPLA2-IIa) is secreted into the circulation by cancer cells and may allow for an early detection of lung cancer.
  
  
  METHODS
  Plasma samples from healthy donors, patients with only benign SPN, and patients with lung cancer were analyzed. Expression of sPLA2-IIa protein in lung cancer tissues was also determined.
  
  
  RESULTS
  We found that the levels of plasma sPLA2-IIa were significantly elevated in lung cancer patients. The receiver operating characteristic curve analysis, comparing lung cancer patients to patients with benign nodules, revealed an optimum cutoff value for plasma sPLA2-IIa of 2.4 ng/ml to predict an early stage cancer with 48% sensitivity and 86% specificity and up to 67% sensitivity for T2 stage lung cancer. Combined sPLA2-IIa, CEA, and Cyfra21.1 tests increased the sensitivity for lung cancer prediction. High level of plasma sPLA2-IIa was associated with a decreased overall cancer survival. sPLA2-IIa was overexpressed in almost all non-small cell lung cancer and in the majority of small cell lung cancer by immunohistochemistry analysis.
  
  
  CONCLUSIONS
  Our finding strongly suggests that plasma sPLA2-IIa is a potential lung biomarker to distinguish benign nodules from lung cancer and to aid lung cancer diagnosis in patients with SPNs.
authors.affiliation: Department of Cancer and Cell Biology, University of Cincinnati College of Medicine, UC Metabolic Diseases Institute, 2120 E, Galbraith Road, Building A, Room 259, Cincinnati, OH 45237-0507, USA.
authors.forename: Elena
authors.initials: E
authors.lastname: Kupert
authors.forename: Marshall
authors.initials: M
authors.lastname: Anderson
authors.forename: Yin
authors.initials: Y
authors.lastname: Liu
authors.forename: Paul
authors.initials: P
authors.lastname: Succop
authors.forename: Linda
authors.initials: L
authors.lastname: Levin
authors.forename: Jiang
authors.initials: J
authors.lastname: Wang
authors.forename: Kathryn
authors.initials: K
authors.lastname: Wikenheiser-brokamp
authors.forename: Pingping
authors.initials: P
authors.lastname: Chen
authors.forename: Susan M
authors.initials: SM
authors.lastname: Pinney
authors.forename: Trudy
authors.initials: T
authors.lastname: Macdonald
authors.forename: Zhongyun
authors.initials: Z
authors.lastname: Dong
authors.forename: Sandra
authors.initials: S
authors.lastname: Starnes
authors.forename: Shan
authors.initials: S
authors.lastname: Lu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D042241:Early Diagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D054501:Group II Phospholipases A2 / Q000097:blood*; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000175:diagnosis / Q000201:enzymology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000175:diagnosis / Q000201:enzymology* / Q000401:mortality; D016019:Survival Analysis
chemical_list: D014408:Biomarkers, Tumor; D054501:Group II Phospholipases A2