TUESDAY, Oct. 19 (HealthDayNews) -- An aspirin that is
"thousands of times more powerful" than traditional forms of
the drug but has no gastrointestinal side effects looks
promising in animal studies, researchers say.
The drug, called nitric oxide-donating aspirin, or
nitroaspirin, appears to help prevent colon cancer in mice
without raising the incidence of gastrointestinal bleeding,
researchers reported Oct. 19 at the American Association for
Cancer Research meeting in Seattle.
Although the findings are "preliminary," the drug may be
also help protect against cardiovascular disease and ease
arthritis pain, said researcher Dr. Basil Rigas, chief of the
Division of Cancer Prevention at SUNY Stony Brook, New
"My laboratory has been working with this compound for the
last five years and it has two striking features -- one, it's
much more potent than regular aspirin, and secondly, it's much
safer," he said.
Clinical trials involving the use of nitroaspirin in 240
patients at high risk for colon polyps and colon cancer are
expected to begin "over the next few months," he added.
Doctors have long known that aspirin -- a drug first
discovered more than 100 hundred years ago -- prevents or
treats a number of common ailments. However, aspirin, like
other members of the non-steroidal anti-inflammatory (NSAID)
family of drugs, tends to raise risks for gastrointestinal
bleeding in long-term users.
In fact, popular cox-2 arthritis medications such as
Celebrex, Bextra and Vioxx -- the last of which was recently
withdrawn from the market due to increased risk of heart
attack or stroke -- were successful because they relieved pain
without the gastrointestinal risk inherent in other
Many NSAIDs, including aspirin, also seem to help lower
risks for colon cancer.
"That's actually where some of the initial data on colon
cancer came from, " said Dr. Durado Brooks, director of
prostate and colorectal cancer at the American Cancer Society.
"People who were taking these drugs for arthritis were
coincidentally noticed to have a lower likelihood to have
However, with regular aspirin's gastrointestinal side
effects, scientists have been busy looking for
"It's similar to traditional aspirin, but different in one
way, in that the molecule of aspirin has been modified to
release nitric oxide (NO)," Rigas explained. "Nitric oxide is
a very important molecule that has multiple effects within the
cardiovascular system, the respiratory system and, we are
finding, against cancer."
In their study, Rigas and his colleagues found that mice
engineered to have a high risk of colon tumors that were given
nitroaspirin daily for three weeks displayed a 59 percent
reduction in tumors compared with untreated mice. And there
were no signs of increased gastrointestinal toxicity compared
The study was funded by a grant from the National Cancer
Brooks said the findings "look very promising, and it's an
exciting concept." But he stressed that, "we're a long way
from being able to say anything about nitroaspirin's true
value, given that what we've looked at is an animal
He also noted that drugs that look safe in the short-term
can lose their appeal when long-term data arrives.
"Remember, cox-2 inhibitors [such as Vioxx] have been used
for a long time and were felt to be safe and effective -- they
were a form of 'safer aspirin,' too," he said. "So who knows?
Maybe somewhere down the line we may find out about the side
effects of nitroaspirins. We just don't know right now."
Still, Brooks remains cautiously optimistic. The drug could
well prove to be "a single agent that helps decrease the
incidence of heart disease as well as decreasing colon cancer
risk," he said. "It might even be a chemotherapeutic agent for
someone who has a colon polyp identified -- you give them this
to make it go away."
Rigas agreed the findings are preliminary, but he said the
drug's potential impact could be enormous. "Our investigators
have studied this for prophylaxis against heart disease, also
against arthritis," he said. "It's up to 5,000 times more
powerful than regular aspirin, and a lot safer."
To learn more about NSAIDS, visit the Arthritis Foundation.
Last Updated: Oct-19-2004
SOURCES: Basil Rigas, M.D., Ph.D., chief, Division
of Cancer Prevention, SUNY Stony Brook, Stony Brook, N.Y.;
Durado Brooks, M.D., M.P.H., director, prostate and colorectal
cancer, American Cancer Society; Oct. 19, 2004, presentation,
American Association for Cancer Research meeting, Seattle
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