Study Suggests Aspirin May Help Prevent Ovarian Cancer

Aspirin’s potential as an ovarian cancer preventive gained support last week, with yet another study suggesting it may reduce a woman’s risk of the deadly disease.

The findings, while limited in scope, are generating excitement because currently only oral contraceptives are known to reduce risk. Such research is particularly important because ovarian cancer produces vague symptoms, often leading to a diagnosis when the cancer is already advanced. Each year, about 23,000 U.S. women are diagnosed with the disease, and 13,900 die.

“Our greatest breakthrough in ovarian cancer will come from prevention and early detection,” said Dr. Beth Y. Karlan, a gynecological oncologist at Cedars-Sinai Medical Center. “So there is enthusiasm in the science and advocacy communities to embrace and better understand any potential means for aspirin to decrease ovarian cancer risk.”

However, women at high risk for the disease--such as those with a family history or who carry the BRCA1 or BRCA2 gene--may remain frustrated with researchers’ and doctors’ caution. They don’t recommend taking it for prevention just yet.

“These [new] data are not a reason for women to run out and begin to take aspirin,” Karlan said.

The lead author of the study, Dr. Arslan Akhmedkhanov of New York University School of Medicine, agreed. Although his research, which was funded by the National Cancer Institute, found that women taking aspirin three or more times a week for at least six months had a 40% reduction in cancer risk, the numbers of women in the study were small.

The research was drawn from participants in the 14,000-member New York University Women’s Health Study, which followed women for 12 years. Akhmedkhanov looked at women who developed ovarian cancer during that time, then asked them to recall their aspirin use--a method of collecting data that is only as good as the participants’ memories. Only 68 women who developed ovarian cancer could also recall their aspirin use.

“We are not advising that women take aspirin right away,” Akhmedkhanov said. “We think additional studies should take place.”

He presented his findings March 6 at the Society of Gynecologic Oncologists’ annual meeting in Nashville, Tenn.

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The study has generated interest because it is the fourth to find a link between aspirin and reduced ovarian cancer risk, Akhmedkhanov said. One other study did not find a benefit to aspirin use.

“Taken together with the previous . . . studies, three of which showed a reduced risk, it’s difficult to say [the decreased risk] is just because of chance,” he said.

There is also a growing body of laboratory and theoretical evidence to explain why aspirin may help prevent some types of cancer.

For example, ovarian cancer may be related to chronic inflammation, said James Lacey Jr., a research fellow at the National Cancer Institute. “Therefore, anti-inflammatories like aspirin might be associated with a decreased risk if they block inflammation,” he said.

Ovarian cancer might be preceded by inflammation due to pelvic inflammatory disease or the use of talcum powder, both of which are linked to an increased risk of the disease, Akhmedkhanov said. Aspirin reduces inflammation by inhibiting an enzyme called cyclooxygenase, or COX.

There is more evidence that aspirin may help prevent colon cancer than there is for ovarian cancer, Lacey said. And some animal studies show that aspirin may reduce the risk of cancer of the bladder, prostate, uterus, cervix, pancreas, lung and stomach.

But the new study on ovarian cancer, Karlan said, “is provocative and significant because of its timing with our understanding of COX inhibitors and their role in cancer prevention.”

Akhmedkhanov said his research group will turn its attention to aspirin use and the risk of cancer of the uterus, cervix and lung.

“There may be a universal mechanism by which aspirin reduces cancer risk,” he said. “What makes it more interesting is that aspirin is such a common drug.”

That aspirin is so common may also be a problem, however. There is no patent on aspirin, and, as such, drug companies will not be interested in doing research on it for cancer prevention. Funding for aspirin studies will have to be generated from private or government sources, experts say.

Future research will also have to define the risks associated with taking aspirin for possible cancer prevention, Akhmedkhanov said, noting: “The most serious complication of long-term aspirin use is gastrointestinal bleeding.”

Although information on aspirin remains incomplete, women at high risk of ovarian cancer can consider the use of oral contraceptives to reduce their risk, Karlan said.

Women should also be aware, she said, of the subtle symptoms of the disease, including persistent abdominal bloating or pressure, changes in bowel or bladder patterns, lower back pain, abnormal bleeding, fatigue and pain during intercourse.