title: Aberrant crypt foci: endoscopic assessment and cell kinetics characterization.
abstract: OBJECTIVE
  Aberrant crypt foci (ACF) are preneoplastic lesions in animal models of colorectal cancer. The aim of the study is to investigate if ACF are involved in human colorectal carcinogenic process and if they can be helpful in predicting the presence of a colorectal neoplasia.
  
  
  METHODS
  The study included, between 2003 and 2005, 182 patients, 62 with adenoma, 55 with colorectal carcinoma, 53 without colorectal lesions, and 12 with nonneoplastic mucosal polyps. The number of rectal ACF was determined by colonoscopy. Proliferation and apoptosis indexes were evaluated by immunohistochemistry in rectal ACF, in normal rectal mucosa, and in carcinomatous tissue.
  
  
  RESULTS
  The mean number of rectal ACF in patients with rectal neoplasia was 12.64, significantly higher than in patients with neoplastic lesions elsewhere in the colon (p=0.01). The apoptosis index in ACF of patients with colorectal carcinoma or adenoma aged 50 years or older was significantly lower than in younger patients (1.3% vs 2.7%, p=0.01) and, in patients with carcinoma, lower than in normal mucosa (1.1% vs 2.1%, p=0.002). The proliferation index was significantly higher in ACF of patients with colorectal neoplasia aged less than 50 years than in normal mucosa (10.9% vs 7.7%, p=0.02). The apoptosis index in ACF foci of patients with carcinoma (1.1%) was significantly lower than in patients without lesions (2.2%) and than in normal mucosa (2%). The mean number of ACF is significantly higher in patients with polyps larger than 1 cm (11.28 vs 6.27, p=0.02).
  
  
  CONCLUSIONS
  Aberrant crypt foci probably precede the appearance of neoplasia and may be helpful in predicting the presence of a colorectal neoplastic lesion.
authors.affiliation: Department of Gastroenterology, Hospitais da Universidade de Coimbra, Avenida Bissaya Barreto, 3000-075 Coimbra, Portugal. pedro.n.figueiredo@clix.pt
authors.forename: Pedro
authors.initials: P
authors.lastname: Figueiredo
authors.forename: Maria
authors.initials: M
authors.lastname: Donato
authors.forename: Marta
authors.initials: M
authors.lastname: Urbano
authors.forename: Helena
authors.initials: H
authors.lastname: Goulão
authors.forename: Hermano
authors.initials: H
authors.lastname: Gouveia
authors.forename: Carlos
authors.initials: C
authors.lastname: Sofia
authors.forename: Maximino
authors.initials: M
authors.lastname: Leitão
authors.forename: Diniz
authors.initials: D
authors.lastname: Freitas