Abstract
As precancerous lesions for large bowel cancers, early appearing lesions like aberrant crypt foci (ACF) are recognized. Recently, we identified β-cetenin accumulated crypts (BCAC) in the colonic mucosa of rats given a colon carcinogen. BCAC have frequent β-catenin gene mutations and their pathological features are different from those of ACF. Further comparative studies on the molecular pathology and biology of both lesions, gave rise to evidences that BCAC are probably the direct precursor for the large intestinal cancers in rodents. The newly identified lesions are suggested to be a reliable biomarker for the risk assessment of environmental chemicals and for the screening of cancer preventing agents.
