title: Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry serum protein profiling to identify nasopharyngeal carcinoma.
abstract: BACKGROUND
  Diagnosis of nasopharyngeal carcinoma (NPC) at an early disease stage is important for successful treatment and improving the outcome of patients. The use of serum protein profiles and a classification tree algorithm were explored to distinguish NPC from noncancer.
  
  
  METHODS
  Serum samples were applied to metal affinity protein chips to generate mass spectra by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Protein peak identification and clustering were performed using the Biomarker Wizard software. Proteomic spectra of serum samples from 50 NPC patients and 54 noncancer controls were used as a training set and a classification tree with 6 distinct protein masses was generated by using Biomarker Pattern software. The validity of the classification tree was then challenged with a blind test set including another 20 NPC patients and 25 noncancer controls.
  
  
  RESULTS
  The software identified an average of 93 mass peaks/spectrum and 6 of the identified peaks were used to construct the classification tree. The classification tree correctly determined 83% (123 of 149) of the test samples with 83% (58 of 70) of the NPC samples and 82% (65 of 79) of the noncancer samples. In a combination of the serum protein profiles with Epstein-Barr (EBV) nuclear antigen 1 (EBNA1 IgA) test, the diagnostic sensitivity and specificity were increased to 99% and 96%, respectively.
  
  
  CONCLUSIONS
  The results suggest that SELDI-TOF-MS serum protein profiles could discriminate NPC from noncancer. The combination of serum protein profiles with an EBV antibody serology test could further improve the accuracy of NPC screening.
authors.affiliation: Department of Surgery, University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: David Wing Yuen
authors.initials: DW
authors.lastname: Ho
authors.forename: Zhen Fan
authors.initials: ZF
authors.lastname: Yang
authors.forename: Birgitta Yee-Hang
authors.initials: BY
authors.lastname: Wong
authors.forename: Dora Lai-Wan
authors.initials: DL
authors.lastname: Kwong
authors.forename: Jonathan Shun-Tong
authors.initials: JS
authors.lastname: Sham
authors.forename: William Ignace
authors.initials: WI
authors.lastname: Wei
authors.forename: Anthony Po Wing
authors.initials: AP
authors.lastname: Yuen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D015415:Biomarkers / Q000097:blood*; D003663:Decision Trees; D005260:Female; D006801:Humans; D008297:Male; D046208:Microchip Analytical Procedures; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000097:blood / Q000145:classification* / Q000175:diagnosis*; D009363:Neoplasm Proteins / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013499:Surface Properties
chemical_list: D015415:Biomarkers; D009363:Neoplasm Proteins