Current concepts in colorectal cancer prevention.

Colorectal cancer chemoprevention, or chemoprophylaxis, is a drug-based approach to prevent colorectal cancer. Preventing colorectal adenomas with currently available agents demonstrates the promise of pharmacologic strategies directed at critical regulatory pathways. However, agent toxicity, lesion breakthrough and competing efficacy from endoscopy procedures challenge population-based implementation. This article reviews the role of colorectal cancer chemoprevention in the context of existing screening and surveillance guidelines and practice. Emphasis is placed on the role of the colorectal adenoma as a cancer precursor and its surrogacy in assessing individual risk and for evaluating chemoprevention efficacy. We discuss the importance of risk stratification for identifying subjects at moderate-to-high risk for colorectal cancer who are most likely to benefit from chemoprevention at an acceptable level of risk.