Mechanisms of aspirin chemoprevention of colorectal cancer.

Good evidence indicates that the regular consumption of aspirin reduces the risk of colorectal cancer by up to 50%. This paper discusses mechanisms for this protection and considers carcinogen activation, cell proliferation, apoptosis and immune surveillance. It is not clear, however, whether these mechanisms are dose related. This question will remain to be answered until the optimum dose and duration of aspirin required for protection against colorectal cancer is established.