Proliferation and differentiation biomarkers in colorectal mucosa and their application to chemoprevention studies.

Colorectal cancer is one of the leading causes of morbidity and mortality in Western countries. Because its prognosis is relatively unaffected by improvements in surgery and chemotherapy, increasing interest has recently been directed toward chemoprevention. Intermediate biomarkers of abnormal cell proliferation, differentiation, and gene expression have recently been identified and have served to measure effects of chemopreventive agents in rodent models and in short-term human clinical trials. Alterations in cell proliferation and differentiation have been found in preneoplastic diseases and in normal-appearing colorectal mucosa of patients at increased risk for malignancy. Several techniques are available for measuring these alterations, and standardization and comparison of different methods are underway to assess the utility of various intermediate biomarkers in chemoprevention studies.