title: A simplified, non-invasive fecal-based DNA integrity assay and iFOBT for colorectal cancer detection.
abstract: OBJECTIVE
  Neoplasia cells exfoliated from colorectal epithelium have dysfunctional apoptotic mechanisms, thus it is possible to identify high-molecular weight DNA fragments in feces. This prospective single-center study was performed to evaluate the sensitivity and specificity of fecal-based DNA integrity versus immunological fecal occult blood test (iFOBT) and calprotectin for colorectal cancer (CRC) and adenoma detection.
  
  
  METHODS
  Feces were collected from 204 subjects and DNA integrity was quantified by quantitative-denaturing high performance liquid chromatography (QdHPLC). Calprotectin and iFOBT were assessed using commercial kits. The diagnostic performance was calculated by receiver operating characteristic (ROC) curves analysis.
  
  
  RESULTS
  A total of 192 fecal specimens were analyzed and 12 samples were excluded due to DNA degradation. We found long DNA (L-DNA) occurrence in feces with a sensitivity of 86% (n = 24/28) and a specificity of 81% for CRC detection. To minimize false-positive cases of the developed test, area under the curve of ROC was evaluated such that the specificity was increased to 92% with decreased sensitivity to 79%, p = 0.0001 for CRC detection. iFOBT was positive in 51% (n = 14/27) while calprotectin was positive in 75% (n = 18/27). The combination of iFOBT and L-DNA identified a greater number of CRC cases with a sensitivity of 89% and a specificity of 95%, p < 0.001. The combination also improved the sensitivity of polyps, particularly high-grade dysplasia and advanced adenoma (33%, p = 0.0015) as opposed to a single evaluation assay (17-21%).
  
  
  CONCLUSIONS
  This study illustrates the usefulness of fecal DNA integrity assay by QdHPLC as a non-invasive, easy-to-perform, and reproducible method with a high level of sensitivity in detecting individuals with colorectal neoplasia. Combination of iFOBT and L-DNA improves the sensitivity for CRC and adenoma detection.
authors.affiliation: Department of Internal Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy. m.kalimutho@qub.ac.uk
authors.forename: Murugan
authors.initials: M
authors.lastname: Kalimutho
authors.forename: Giovanna
authors.initials: G
authors.lastname: Del Vecchio Blanco
authors.forename: Micaela
authors.initials: M
authors.lastname: Cretella
authors.forename: Elena
authors.initials: E
authors.lastname: Mannisi
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Sileri
authors.forename: Amanda
authors.initials: A
authors.lastname: Formosa
authors.forename: Francesco
authors.initials: F
authors.lastname: Pallone
authors.forename: Giorgio
authors.initials: G
authors.lastname: Federici
authors.forename: Sergio
authors.initials: S
authors.lastname: Bernardini
mesh_terms: D000236:Adenoma / Q000175:diagnosis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001681:Biological Assay / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D004247:DNA / Q000032:analysis*; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D039841:Leukocyte L1 Antigen Complex / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009691:Nucleic Acid Denaturation; D009780:Occult Blood; D012372:ROC Curve; D012044:Regression Analysis; D012680:Sensitivity and Specificity
chemical_list: D039841:Leukocyte L1 Antigen Complex; D004247:DNA