Can Aspirin Prevent Ovarian Cancer?
You've heard that "an apple a day
keeps the doctor away" -- maybe we should change that to "An aspirin a day.
. .". You've also heard doctors recommend that men over age 40 and women at
increased risk for heart disease take a baby aspirin a day to reduce heart disease
risk. Now women may have even more reason to consider aspirin therapy. A study
reported at the Society of Gynecologic Oncologists annual meeting (3/6/01) suggests
that long-term aspirin use may decrease the risk of the most common form of
ovarian cancer.
This prospective study evaluated 748 women for an
average of 12 years. Initial results suggest that aspirin use three or more
times per week for at least six months may reduce the risk of epithelial ovarian
cancer by 40%. The study was conducted by Dr. Arslan Akhmedkhanov M.D. and his
colleagues at New York University School of Medicine, New York and Dr. I. Kato,
M. D., Ph.D., at Wayne State University in Detroit. "Evidence suggests that
chronic inflammation, similar to the inflammation seen in endometriosis and
pelvic inflammatory disease, could be related to epithelial ovarian cancer,"
said the study's lead author, Arslan Akhmedkhanov, M.D. "One way to evaluate
the role of inflammation in ovarian cancer is to examine the effect of common
anti-inflammatory medications, such as aspirin on epithelial ovarian cancer
risk. Our data, combined with other similar research indicates aspirin may have
broader anticarcinogenic properties than previously thought."
The study was conducted using a series of questionnaires.
At the time of enrollment, women answered a questionnaire covering a variety
of topics from demographics to reproductive data to medical history. After
the initial questionnaire, follow-up questionnaires were sent every two years
to update the information on potential risk factors and to identify newly diagnosed
cases of cancer and other medical conditions.
From 1994 to 1996, detailed data on aspirin use was
collected using the following question: Have you taken aspirin three or more
times per week for a period of six months or longer? For women who answered
"yes", additional information regarding the dose and duration of aspirin use
was requested. A total of 140 women with ovarian cancer were identified after
the average follow-up period of 12 years. Of these, 68 women responded to questions
on aspirin use in the 1994 --1996 follow-up questionnaire and were diagnosed
with common types of epithelial ovarian cancer.
Ten matched controls per case
were selected at random among cancer-free cohort members. As a result, 748 women
were available for analysis, including 68 women with epithelial ovarian cancer
and 680 matched controls.
One weakness of the study is its relatively small
sample size and its reliance on women's recall about their aspirin use. According
to Dr. Akhmedkhanov, "If confirmed by larger prospective studies, these results
could have a considerable impact on the treatment and prevention of gynecologic
cancers, as well as spark greater interest in researching the broader anticancer
effects that aspirin may hold".
This information is still considered a research hypothesis.
Because there are risks associated with regular aspirin use, women should consult
with their physicians before starting any long-term aspirin regimens.
According to Dr. Akhmedkhanov, four other case-control
studies have addressed the role of aspirin and other non-steroidal anti-inflammatory
drugs (NSAIDs) in ovarian cancer. Three of these studies suggested a protective
benefit of regular aspirin and other NSAID use in ovarian cancer. One study
found no effect. A recent case-control surveillance study of medication use
and cancer, including 780 women with epithelial ovarian cancer from Baltimore,
Boston, New York, and Philadelphia, found a 50 percent reduction in epithelial
ovarian cancer risk when aspirin was used four or more times per week for at
least five years. These results are comparable to the results of this most recent
study.
Why is this news particularly exciting? First of
all, it's welcome news because ovarian cancer has an insidious onset and it's
often difficult to diagnose. In addition, there are no reliable screening tests
for ovarian cancer. Ovarian cancer is the most serious cancer affecting women's
reproductive organs. It ranks fifth as a cause of cancer deaths among women,
and causes more deaths than any other cancer of the female reproductive system.
The Society of Gynecologic Oncologists estimates that there will be 23,400 new
cases of ovarian cancer diagnosed and approximately 14,000 deaths from ovarian
cancer in the United States during 2001 alone.
Ovarian cancer usually arises on the surface of the ovary in the epithelial
layer --this was the type of ovarian cancer diagnosed in this study. We know
several risk factors for ovarian cancer -- increasing age, family history of
ovarian cancer, infertility, not having given birth, and having a genetic mutation
for breast cancer. Interestingly, the only known factors that decrease the
risk of ovarian cancer are each additional pregnancy a woman has and taking
birth control pills for at least 5 years. Taking birth control pills for at
least 5 years may reduce a woman's risk of ovarian cancer by 40% to 60%, slightly
more than the risk reduction suggested for aspirin in this study.
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Created: 3/8/2001  - Donnica Moore, M.D.