title: A new biomarker panel in bronchoalveolar lavage for an improved lung cancer diagnosis.
abstract: BACKGROUND
  The enormous biological complexity and high mortality rate of lung cancer highlights the need for new global approaches for the discovery of reliable early diagnostic biomarkers. The study of bronchoalveolar lavage samples by proteomic techniques could identify new lung cancer biomarkers and may provide promising noninvasive diagnostic tools able to enhance the sensitivity of current methods.
  
  
  METHODS
  First, an observational prospective study was designed to assess protein expression differences in bronchoalveolar lavages from patients with (n = 139) and without (n = 49) lung cancer, using two-dimensional gel electrophoresis and subsequent protein identification by mass spectrometry. Second, validation of candidate biomarkers was performed by bead-based immunoassays with a different patient cohort (204 patients, 48 controls).
  
  
  RESULTS
  Thirty-two differentially expressed proteins were identified in bronchoalveolar lavages, 10 of which were confirmed by immunoassays. The expression levels of APOA1, CO4A, CRP, GSTP1, and SAMP led to a lung cancer diagnostic panel that reached 95% sensitivity and 81% specificity, and the quantification of STMN1 and GSTP1 proteins allowed the two main lung cancer subtypes to be discriminated with 90% sensitivity and 57% specificity.
  
  
  CONCLUSIONS
  Bronchoalveolar lavage represents a promising noninvasive source of lung cancer specific protein biomarkers with high diagnostic accuracy. Measurement of APOA1, CO4A, CRP, GSTP1, SAMP, and STMN1 in this fluid may be a useful tool for lung cancer diagnosis, although a further validation in a larger clinical set is required for early stages.
authors.affiliation: *Department of Research and Development, Proteomika SLU, Derio, Spain; and the †Department of Respiratory Medicine and ‡Medical Oncology Research Laboratory, Cruces Hospital, Barakaldo, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Uribarri
authors.forename: Itsaso
authors.initials: I
authors.lastname: Hormaeche
authors.forename: Rafael
authors.initials: R
authors.lastname: Zalacain
authors.forename: Guillermo
authors.initials: G
authors.lastname: Lopez-Vivanco
authors.forename: Antonio
authors.initials: A
authors.lastname: Martinez
authors.forename: Daniel
authors.initials: D
authors.lastname: Nagore
authors.forename: M Begoña
authors.initials: MB
authors.lastname: Ruiz-Argüello
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D018893:Bronchoalveolar Lavage / Q000379:methods*; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D018288:Carcinoma, Small Cell / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies
chemical_list: D014408:Biomarkers, Tumor