By Marlowe Hood
Posted in AOL.com on 12/07/2010
PARIS, France—A small, daily dose of
aspirin significantly diminishes the risk of death from
a wide range of cancers, according to a landmark study
released Tuesday.
Earlier work by the same team of
scientists showed that the century-old remedy for
aches and pains,
long a staple of family
pharmacies,
can help ward off colon cancer.
The new study, published in the British
medical journal The Lancet, reveals for the first time
that aspirin also helps protect against prostate, lung,
brain, and throat cancers, among others.
"These findings provide the first proof
in man that aspirin reduces deaths due to several common
cancers," said Peter Rothwell, a professor at the
University of Oxford and lead author of the study.
Rothwell and colleagues reviewed eight
previous clinical trials involving a total of more than
25,500
patients.
In each, some subjects took aspirin and others
look-alike placebos.
None of the studies were originally
designed to measure the impact of the drug on the
incidence of cancer.
During the trials, which lasted
four-to-eight years, doses of aspirin as low as 75
milligrams—a fraction the normal dose for a headache—cut
cancer deaths overall by 21 percent.
Risk was especially reduced after five
years of treatment with the drug, by 30 to 40 percent
depending on the type of cancer.
Three of the eight trials ran long enough
to examine the impact of aspirin over a period of two
decades.
The 20-year risk dropped on average by a
fifth: 10 percent for prostate cancer, 30 percent for
lung cancer, 40 percent for colon cancer, and 60 percent
for esophageal cancer.
For cancer of the lung and throat, the
protective effect was confined to adenocarcinomas, the
type typically seen in non-smokers.
"Perhaps the most important finding for
the longer term is the proof of principle that cancers
can be prevented by simple compounds like aspirin, and
that 'chemo-prevention' is therefore a realistic goal,"
Rothwell said.
The length of time before the benefits of
taking aspirin kicked in also varied: five years for
throat, pancreatic, brain, and lung cancer, about 10
years for stomach and colorectal cancer, and 15 years
for
prostate cancer.
The reductions in stomach and brain
cancers, however, were more difficult to quantify
because of the smaller number of deaths recorded.
"These promising results build on a large
body of evidence suggesting that aspirin could reduce
the risk of developing or dying from many different
types of cancer," said Ed Yong of Cancer Research UK in
commenting on the study.
"This tells us that even small doses
reduce the risk of dying from cancer provided it is
taken for at least five years."
Many
doctors
recommend regular use of aspirin to lower the risk of
heart attack, clot-related strokes, and other blood flow
problems.
But daily use of the drug, available
without prescription, may cause stomach problems,
including stomach bleeding. Alcohol use can aggravate
these symptoms.
"We encourage anyone interested in taking
aspirin on a regular basis to talk to their doctor
first," Yong said.
Aspirin is believed to have a preventive
effect because it inhibits an enzyme called COX-2, which
promotes cell proliferation in cancer tumors.
In rich nations, the lifetime risk of
developing cancer is about 40 percent, with rates in the
developing world increasing.
Tim
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