title: Rectal Optical Markers for In Vivo Risk Stratification of Premalignant Colorectal Lesions.
abstract: OBJECTIVE
  Colorectal cancer remains the second leading cause of cancer deaths in the United States despite being eminently preventable by colonoscopy via removal of premalignant adenomas. In order to more effectively reduce colorectal cancer mortality, improved screening paradigms are needed. Our group pioneered the use of low-coherence enhanced backscattering (LEBS) spectroscopy to detect the presence of adenomas throughout the colon via optical interrogation of the rectal mucosa. In a previous ex vivo biopsy study of 219 patients, LEBS demonstrated excellent diagnostic potential with 89.5% accuracy for advanced adenomas. The objective of the current cross-sectional study is to assess the viability of rectal LEBS in vivo.
  
  
  METHODS
  Measurements from 619 patients were taken using a minimally invasive 3.4-mm diameter LEBS probe introduced into the rectum via anoscope or direct insertion, requiring approximately 1 minute from probe insertion to withdrawal. The diagnostic LEBS marker was formed as a logistic regression of the optical reduced scattering coefficient [Formula: see text] and mass density distribution factor D.
  
  
  RESULTS
  The rectal LEBS marker was significantly altered in patients harboring advanced adenomas and multiple non-advanced adenomas throughout the colon. Blinded and cross-validated test performance characteristics showed 88% sensitivity to advanced adenomas, 71% sensitivity to multiple non-advanced adenomas, and 72% specificity in the validation set.
  
  
  CONCLUSIONS
  We demonstrate the viability of in vivo LEBS measurement of histologically normal rectal mucosa to predict the presence of clinically relevant adenomas throughout the colon. The current work represents the next step in the development of rectal LEBS as a tool for colorectal cancer risk stratification.
authors.affiliation: Biomedical Engineering Department, Northwestern University, Evanston, Il.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Radosevich
authors.affiliation: Biomedical Engineering Department, Northwestern University, Evanston, Il.
authors.forename: Nikhil N
authors.initials: NN
authors.lastname: Mutyal
authors.affiliation: Biomedical Engineering Department, Northwestern University, Evanston, Il.
authors.forename: Adam
authors.initials: A
authors.lastname: Eshein
authors.affiliation: Biomedical Engineering Department, Northwestern University, Evanston, Il.
authors.forename: The-Quyen
authors.initials: TQ
authors.lastname: Nguyen
authors.affiliation: Biomedical Engineering Department, Northwestern University, Evanston, Il.
authors.forename: Bradley
authors.initials: B
authors.lastname: Gould
authors.affiliation: Biomedical Engineering Department, University of Wisconsin, Madison, Wisconsin.
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Rogers
authors.affiliation: Department of Medicine, NorthShore University HealthSystems, Evanston, Il.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Goldberg
authors.affiliation: Department of Medicine, NorthShore University HealthSystems, Evanston, Il.
authors.forename: Laura K
authors.initials: LK
authors.lastname: Bianchi
authors.affiliation: Department of Medicine, NorthShore University HealthSystems, Evanston, Il.
authors.forename: Eugene F
authors.initials: EF
authors.lastname: Yen
authors.affiliation: Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL.
authors.forename: Vani
authors.initials: V
authors.lastname: Konda
authors.affiliation: Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Douglas K
authors.initials: DK
authors.lastname: Rex
authors.affiliation: Advanced Digestive Health Center, University of Southern California Medical Center, Los Angeles, CA.
authors.forename: Jacques
authors.initials: J
authors.lastname: Van Dam
authors.affiliation: Biomedical Engineering Department, Northwestern University, Evanston, Il.
authors.forename: Vadim
authors.initials: V
authors.lastname: Backman
authors.affiliation: Department of Medicine, Boston University, Boston, Massachusetts.
authors.forename: Hemant K
authors.initials: HK
authors.lastname: Roy
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000473:pathology; D000368:Aged; D015415:Biomarkers; D001706:Biopsy; D016022:Case-Control Studies; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D055088:Early Detection of Cancer / Q000295:instrumentation / Q000379:methods; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D019095:Point-of-Care Systems; D011230:Precancerous Conditions / Q000175:diagnosis* / Q000473:pathology; D012007:Rectum / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D015415:Biomarkers