Aberrant crypt foci (ACF) are microscopic, mucosal lesions consisting of large, thickened crypts first described in mice treated with a carcinogen. ACF similar to those in rodents have also been reported in human colonic mucosa, and recent data suggest that a subset of ACF may be clonal in origin and have the potential to develop into later stage neoplastic lesions (e.g., adenomas and carcinomas). The objectives of this study are to characterize and quantify in vivo ACF within a heterogeneous group of persons: 1) without prior colorectal neoplasia, 2) with adenomas, 3) with carcinomas. The prevalence and characteristics of ACF will then be evaluated for their correlation with more advanced stages of neoplasia, as well as several parameters of cancer risk. Patients with prevalent ACF will then be enrolled into a chemoprevention trial exploring the activity of a few compounds over several months on ACF incidence/regression. Thus the study will determine the prevalence and short-term natural history of ACF in this cohort, and the role of ACF as markers of risk and/or chemopreventive efficacy.
