title: Measuring telomere length for the early detection of precursor lesions of esophageal squamous cell carcinoma.
abstract: BACKGROUND
  Esophageal cancer is the sixth leading cause of cancer death worldwide; current early detection screening tests are inadequate. Esophageal balloon cytology successfully retrieves exfoliated and scraped superficial esophageal epithelial cells, but cytologic reading of these cells has poor sensitivity and specificity for detecting esophageal squamous dysplasia (ESD), the precursor lesion of esophageal squamous cell carcinoma (ESCC). Measuring telomere length, a marker for chromosomal instability, may improve the utility of balloon cytology for detecting ESD and early ESCC.
  
  
  METHODS
  We examined balloon cytology specimens from 89 asymptomatic cases of ESD (37 low-grade and 52 high-grade) and 92 age- and sex-matched normal controls from an esophageal cancer early detection screening study. All subjects also underwent endoscopy and biopsy, and ESD was diagnosed histopathologically. DNA was extracted from the balloon cytology cells, and telomere length was measured by quantitative PCR. A receiver operating characteristic (ROC) curve was plotted for telomere length as a diagnostic marker for high-grade dysplasia.
  
  
  RESULTS
  Telomere lengths were comparable among the low- and high-grade dysplasia cases and controls, with means of 0.96, 0.96, and 0.92, respectively. The area under the ROC curve was 0.55 for telomere length as a diagnostic marker for high-grade dysplasia. Further adjustment for subject characteristics, including sex, age, smoking, drinking, hypertension, and body mass index did not improve the use of telomere length as a marker for ESD.
  
  
  CONCLUSIONS
  Telomere length of esophageal balloon cytology cells was not associated with ESCC precursor lesions. Therefore, telomere length shows little promise as an early detection marker for ESCC in esophageal balloon samples.
authors.affiliation: Division of Cancer Epidemiology & Genetics, National Cancer Institute, 9609 Medical Center Drive, Bethesda, MD 20892, USA. lins4@mail.nih.gov.
authors.forename: Shih-Wen
authors.initials: SW
authors.lastname: Lin
authors.forename: Christian C
authors.initials: CC
authors.lastname: Abnet
authors.forename: Neal D
authors.initials: ND
authors.lastname: Freedman
authors.forename: Gwen
authors.initials: G
authors.lastname: Murphy
authors.forename: Rosana
authors.initials: R
authors.lastname: Risques
authors.forename: Donna
authors.initials: D
authors.lastname: Prunkard
authors.forename: Peter
authors.initials: P
authors.lastname: Rabinovitch
authors.forename: Qin-Jing
authors.initials: QJ
authors.lastname: Pan
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Roth
authors.forename: Guo-Qing
authors.initials: GQ
authors.lastname: Wang
authors.forename: Wen-Qiang
authors.initials: WQ
authors.lastname: Wei
authors.forename: Ning
authors.initials: N
authors.lastname: Lu
authors.forename: Philip R
authors.initials: PR
authors.lastname: Taylor
authors.forename: You-Lin
authors.initials: YL
authors.lastname: Qiao
authors.forename: Sanford M
authors.initials: SM
authors.lastname: Dawsey
mesh_terms: D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000235:genetics*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000235:genetics; D016022:Case-Control Studies; D055088:Early Detection of Cancer; D004938:Esophageal Neoplasms / Q000175:diagnosis* / Q000235:genetics; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D016615:Telomere / Q000235:genetics*; D059505:Telomere Homeostasis
chemical_list: D014408:Biomarkers, Tumor