title: Evaluation of FTIR spectroscopy as a diagnostic tool for lung cancer using sputum.
abstract: BACKGROUND
  Survival time for lung cancer is poor with over 90% of patients dying within five years of diagnosis primarily due to detection at late stage. The main objective of this study was to evaluate Fourier transform infrared spectroscopy (FTIR) as a high throughput and cost effective method for identifying biochemical changes in sputum as biomarkers for detection of lung cancer.
  
  
  METHODS
  Sputum was collected from 25 lung cancer patients in the Medlung observational study and 25 healthy controls. FTIR spectra were generated from sputum cell pellets using infrared wavenumbers within the 1800 to 950 cm-1 "fingerprint" region.
  
  
  RESULTS
  A panel of 92 infrared wavenumbers had absorbances significantly different between cancer and normal sputum spectra and were associated with putative changes in protein, nucleic acid and glycogen levels in tumours. Five prominent significant wavenumbers at 964 cm-1, 1024 cm-1, 1411 cm-1, 1577 cm-1 and 1656 cm-1 separated cancer spectra from normal spectra into two distinct groups using multivariate analysis (group 1: 100% cancer cases; group 2: 92% normal cases). Principal components analysis revealed that these wavenumbers were also able to distinguish lung cancer patients who had previously been diagnosed with breast cancer. No patterns of spectra groupings were associated with inflammation or other diseases of the airways.
  
  
  CONCLUSIONS
  Our results suggest that FTIR applied to sputum might have high sensitivity and specificity in diagnosing lung cancer with potential as a non-invasive, cost-effective and high-throughput method for screening.
  
  
  BACKGROUND
  ClinicalTrials.gov: NCT00899262.
authors.affiliation: Swansea University, UK. p.d.lewis@swansea.ac.uk
authors.forename: Paul D
authors.initials: PD
authors.lastname: Lewis
authors.forename: Keir E
authors.initials: KE
authors.lastname: Lewis
authors.forename: Robin
authors.initials: R
authors.lastname: Ghosal
authors.forename: Sion
authors.initials: S
authors.lastname: Bayliss
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Lloyd
authors.forename: John
authors.initials: J
authors.lastname: Wills
authors.forename: Ruth
authors.initials: R
authors.lastname: Godfrey
authors.forename: Philip
authors.initials: P
authors.lastname: Kloer
authors.forename: Luis A J
authors.initials: LA
authors.lastname: Mur
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D016022:Case-Control Studies; D002986:Clinical Trials as Topic; D005260:Female; D057166:High-Throughput Screening Assays; D006801:Humans; D008175:Lung Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011237:Predictive Value of Tests; D025341:Principal Component Analysis; D012680:Sensitivity and Specificity; D017550:Spectroscopy, Fourier Transform Infrared; D013183:Sputum / Q000737:chemistry*; D014852:Wales
chemical_list: D014408:Biomarkers, Tumor