Attempts at improving outcome from colorectal cancer have recently foc
used on prevention. This paper describes how both surgical and chemoth
erapeutic intervention can cause a fall in cell proliferation, polyp r
egression and a decline in rectal cancer risk in patients with familia
l adenomatous polyposis. Other patients at high risk of colorectal can
cer, or of cancers in other sites, may also have their risks modified
by pharmacological intervention.