The goal of chemoprevention is to modify risk factors that contribute
to the development of cancer before the neoplastic process can be comp
leted. Chemoprevention for colorectal carcinoma has focused on several
groups of drugs that act via different mechanisms. Aspirin and non-st
eroidal anti-inflammatory drugs may prevent colorectal carcinoma by in
hibiting prostaglandin synthesis, specifically by inhibiting the enzym
e cyclooxygenase-2. Fiber may reduce the risk of colorectal carcinoma
by increasing stool bulk, decreasing bowel transport time of potential
carcinogens, or by binding to bile acids or other carcinogens. Calciu
m may be chemoprotective by affecting cellular differentiation and/or
proliferation. The literature evaluating chemoprevention for colorecta
l carcinoma is reviewed here.