Whether it is NSAIDS, statins or any agent, "the science behind inflammation is moving so rapidly that we may now be able to think about designing trials to test agents that will prevent, or delay, several diseases all at once," says Lippman.
Still, none of M. D. Anderson's chemoprevention experts - including Lippman, Lotan, Levin and Hong - suggest that people take a little celecoxib here, a dose of aspirin there, or mix tablespoons of turmeric into their cups of green tea as a way to "self medicate" against cancer.
They all stress that it will take time to prove that any substance can substantially reduce the risk of a disease in the average person without producing side effects. These studies will require giving young and healthy volunteers a drug for many years and then waiting until they have aged to see whether volunteers who used the agent developed fewer diseases compared to those who didn't.
"Like testing whether fluoride in water can prevent cavities, we will not have an answer for 20 to 25 years in the minimum," says Lotan. "You have to make sure that these agents have no side effects if taken for decades, and that is a risk not many drug companies or institutions want to take."
Most chemoprevention studies now test people who are at higher risk of developing cancer, such as former smokers, as a way to predict whether they will help those who are not at risk; few studies are like SELECT in which the only risk factor shared by participants is increased age. At the same time, researchers at M. D. Anderson are actively looking for molecular and genetic risk factors that identify people at highest cancer risk and those most likely to benefit from chemoprevention.
"We must do no harm," says Hong. "A cancer chemoprevention agent, used in young people who are not at risk for cancer, must be absolutely safe and non-toxic."
Levin and others emphasize that chemoprevention must not be substituted for othe
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Contact: Nancy Jensen
nwjensen@mdanderson.org
713-792-0655
University of Texas M. D. Anderson Cancer Center
16-Nov-2004