title: Elevated levels of the acute-phase serum amyloid are associated with heightened lung cancer risk.
abstract: BACKGROUND
  The authors investigated whether early stage lung cancer could be identified by proteomic analyses of plasma.
  
  
  METHODS
  For the first case-control study, plasma samples from 52 patients with lung cancer and from a group of 51 controls were analyzed by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. In a second case-control study, a classifier of 4 markers (mass-to-charge ratio, 11,681, 6843, 5607, and 8762) also was tested for validation on plasma from 16 consecutive patients with screen-detected cancer versus 406 healthy individuals. The most relevant marker was identified, and an enzyme-linked immunosorbent assay-based analysis revealed that signal intensity was correlated with concentration.
  
  
  RESULTS
  The classifier had a sensitivity of 94.23% and a specificity of 76.47% in the first study but lost predictive value in the second study. Nevertheless, the 11,681 cluster, which was identified as serum amyloid protein A (SAA), resulted in a multiple logistic regression model that indicated a strong association with lung cancer. When both studies were considered as a together, the odds ratio (OR) for an SAA intensity > or =0.5 was 10.27 (95% confidence interval [CI], 4.64-22.74), whereas an analysis restricted to stage I cancers (TNM classification) revealed an OR of 8.45 (95% CI, 2.76-25.83) for T1 lung cancer and 21.22 (95% CI, 5.62-80.14) for T2 lung cancer.
  
  
  CONCLUSIONS
  SAA levels were predictive of an elevated risk of lung cancer, supporting the general view that inflammation is implicated in lung cancer development.
authors.affiliation: Department of Experimental Oncology and Laboratory, National Cancer Institute, Milan, Italy.
authors.forename: Mattia
authors.initials: M
authors.lastname: Cremona
authors.forename: Elisa
authors.initials: E
authors.lastname: Calabrò
authors.forename: Giorgia
authors.initials: G
authors.lastname: Randi
authors.forename: Maida
authors.initials: M
authors.lastname: De Bortoli
authors.forename: Piera
authors.initials: P
authors.lastname: Mondellini
authors.forename: Carla
authors.initials: C
authors.lastname: Verri
authors.forename: Gabriella
authors.initials: G
authors.lastname: Sozzi
authors.forename: Marco A
authors.initials: MA
authors.lastname: Pierotti
authors.forename: Carlo
authors.initials: C
authors.lastname: La Vecchia
authors.forename: Ugo
authors.initials: U
authors.lastname: Pastorino
authors.forename: Italia
authors.initials: I
authors.lastname: Bongarzone
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007249:Inflammation / Q000150:complications; D008175:Lung Neoplasms / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012306:Risk; D012680:Sensitivity and Specificity; D000685:Serum Amyloid A Protein / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D014408:Biomarkers, Tumor; D000685:Serum Amyloid A Protein; D002097:C-Reactive Protein