title: A new method for isolating colonocytes from naturally evacuated feces and its clinical application to colorectal cancer diagnosis.
abstract: OBJECTIVE
  The early detection of colorectal cancer is desired because this cancer can be cured surgically if diagnosed early. The purpose of the present study was to determine the feasibility of a new methodology for isolating colonocytes from naturally evacuated feces, followed by cytology or molecular biology of the colonocytes to detect colorectal cancer originating from any part of the colorectum.
  
  
  METHODS
  Several simulation studies were conducted to establish the optimal methods for retrieving colonocytes from any portion of feces. Colonocytes exfoliated into feces, which had been retrieved from 116 patients with colorectal cancer and 83 healthy volunteers, were analyzed. Part of the exfoliated colonocytes was examined cytologically, whereas the remainder was subjected to DNA analysis. The extracted DNA was examined for mutations of the APC, K-ras, and p53 genes using direct sequence analysis and was also subjected to microsatellite instability (MSI) analysis.
  
  
  RESULTS
  In the DNA analysis, the overall sensitivity and specificity were 71% (82 of 116) of patients with colorectal cancer and 88% (73 of 83) of healthy volunteers. The sensitivity for Dukes A and B was 72% (44 of 61). Furthermore, the sensitivity for cancers on the right side of the colon was 57% (20 of 35). The detection rate for genetic alterations using our methodology was 86% (80 of 93) when the analysis was limited to cases in which genetic alterations were present in the cancer tissue.
  
  
  CONCLUSIONS
  We have developed a new methodology for isolating colonocytes from feces. The present study describes a promising procedure for future clinical evaluations and the early detection of colorectal cancers, including right-side colon cancer.
authors.affiliation: Investigative Treatment Division, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Japan.
authors.forename: Hisayuki
authors.initials: H
authors.lastname: Matsushita
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Matsumura
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Moriya
authors.forename: Takayuki
authors.initials: T
authors.lastname: Akasu
authors.forename: Shin
authors.initials: S
authors.lastname: Fujita
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Shigeki
authors.initials: S
authors.lastname: Onouchi
authors.forename: Norio
authors.initials: N
authors.lastname: Saito
authors.forename: Masanori
authors.initials: M
authors.lastname: Sugito
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ito
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kozu
authors.forename: Takashi
authors.initials: T
authors.lastname: Minowa
authors.forename: Sayuri
authors.initials: S
authors.lastname: Nomura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsunoda
authors.forename: Tadao
authors.initials: T
authors.lastname: Kakizoe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor; D003106:Colon / Q000166:cytology*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology*; D004252:DNA Mutational Analysis; D005243:Feces / Q000166:cytology*; D005260:Female; D006801:Humans; D018189:Immunomagnetic Separation; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D014408:Biomarkers, Tumor