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May Block Other Cancers, Too
Aspirin, Ibuprofen
May Reduce Woman’s Risk Of Developing Breast Cancer by Up to 50%
July 16, 2003 - –
New research suggests that regular ibuprofen use may cut a woman’s
risk of developing breast cancer in half.
Findings prepared
for the annual meeting of the
American Association of Cancer Research in Washington, D.C.,
indicate that using ibuprofen – a non-steroidal anti-inflammatory drug
(NSAID) – on a regular basis for more than 10 years may decrease a
woman’s chance by nearly 50 percent that she will develop breast
cancer.
Using aspirin –
another NSAID – reduced breast cancer risk by about 22 percent, said
Randall Harris, the study’s lead author and the co-director of the
Center of Molecular Epidemiology and Environmental Health at Ohio
State University.
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“This translates into an approximately 30 percent reduction (in
breast cancer) for all NSAID users, and a 50 percent reduction in
risk among ibuprofen users.”
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He and his
colleagues used data from a survey that followed nearly 81,000 women
for four years to determine what effect NSAIDs had on decreasing the
incidence of breast cancer. These women were some of more than 100,000
women participating in the
Women’s Health Initiative, an ongoing nationwide study sponsored
by the
National Institutes of Health that looks at a variety of women’s
health issues.
“We’re discovering
that these compounds – NSAIDs – aren’t just for pain and inflammation
relief,” said Harris, who is also the co-principal investigator of the
Women’s Health Initiative clinical center at Ohio State. “This study
shows that these drugs also have significant anticancer effects.”
The NSAIDs
examined in this study included over-the-counter medications such as
ibuprofen and aspirin.
At the outset of
this study, 80,741 postmenopausal women aged 50 to 79 were asked how
often and for how long they had used NSAIDs. These women were selected
because they had no personal history of cancer.
Each participant
was also asked a series of questions that helped researchers evaluate
her risk of developing breast cancer – questions such as how often she
exercised, her body mass, if she had ever given birth, if she was on
estrogen therapy, and if she had a family history of cancer. The
researchers put the women into two groups: those who reported taking
NSAIDs on a regular basis – two or more tablets a week – and those who
either seldom or never took NSAIDs.
The participants
completed health interviews yearly for four years. During that time,
1,392 women – or 1.7 percent of those enrolled in the study --
developed breast cancer.
Women who
regularly took NSAIDs for five to nine years had a 21 percent
reduction in the incidence of breast cancer. Women taking these drugs
on a regular basis for 10 or more years had a 28 percent reduction in
the risk of developing the disease. It wasn’t until the researchers
separated these women further into groups based on the type of NSAID
they took that the effect of ibuprofen vs. aspirin became clear.
“The results
suggest that there were about 150 fewer breast cancer cases per
100,000 women each year among NSAID users vs. those who didn’t use
NSAIDs,” Harris said. “This translates into an approximately 30
percent reduction for all NSAID users, and a 50 percent reduction in
risk among ibuprofen users.”
Even women in
high-risk groups – those who were obese, those who had never given
birth or gave birth later in life, those with a family history of
breast cancer, etc. – still had the same level of reduction if they
were regular NSAID users.
Harris thinks the
reason that NSAIDs – particularly ibuprofen – have such a powerful
effect is due to their ability to block the inflammatory process.
Scientists believe these drugs block the gene responsible for
triggering inflammation in the body. For unknown reasons, this gene,
COX-2, is inappropriately turned on – and stays on – in breast and
other types of cancer.
“We think that
NSAIDs turn off unnecessary inflammation by blocking COX-2,” Harris
said. “Toning down this kind of dysfunctional, uncontrolled
inflammation can block critical steps in tumor development, such as
cell division, the growth of new blood vessels and the spread of the
tumor to other areas of the body.
“I don’t know what
turns COX-2 on, or why it gets stuck in the on position. But it’s bad
news if it does get stuck, because it motivates all these steps to
carcinogenesis.”
Evidence is
mounting that NSAIDs may also help in the treatment and prevention of
other cancers.
“There’s too much
converging and compelling evidence to deny the effects of NSAIDs,”
Harris said. “Most malignant tumors, including colon, breast,
prostate, and lung, appear to be inhibited by NSAID use.”
These drugs may
have side effects in a small percentage of people, said Harris, the
most common of which is an upset or irritated stomach.
“If you’re going
to be a regular ibuprofen or aspirin user, tell your physician,” he
said, adding that he takes 200 mg of ibuprofen daily.
“There is no
recommended guideline for when or if to start taking NSAIDs,” he
continued. “The evidence is compelling that these compounds do protect
women who are 40 and older, but they need to be taken for a few years.
It’s the sustained inhibition of COX-2 that impedes the risk of
carcinogenesis.”
Harris has worked
on the link between NSAIDs and breast cancer since the late 1980s. He
and his colleagues also suspect that NSAIDs may have a role in
treating or helping to prevent other cancers, such as colon, prostate
and lung cancers.
This research was
originally scheduled for presentation in April at the
American Association of Cancer Research meeting in Toronto. That
meeting was rescheduled due to the SARS epidemic.
This research was
supported by funds from the
National Heart, Lung and Blood Institute and the
National Cancer Institute.
Harris conducted
this study with Ohio State researchers Rebecca Jackson and David Frid;
Rowan Chlebowski, of the Harbor-UCLA Research and Education Institute;
Garnet Anderson, Emily White and Anne McTiernan, Aimee Sparks and
Rebecca Rodabaugh, all with the Fred Hutchinson Cancer Research Center
in Seattle; and Joao Ascenseo, of George Washington University in
Washington, D.C. |