Aspirin May Reduce Ovarian Cancer Risk

A daily aspirin may reduce the risk of ovarian cancer, a new study suggests. Further research will be needed to confirm the finding.

More than 20,000 women nationwide are expected to be diagnosed with ovarian cancer in 2014, and at least 14,000 will likely die from the disease. If caught early, ovarian cancer can often be successfully treated. However, its symptoms can mimic more common conditions, such as digestive and bladder disorders, so it’s usually not diagnosed until advanced stages. Late-stage ovarian cancer leaves women with limited treatment options and poor prognoses, making prevention particularly important.

Chronic or persistent inflammation is known to raise the risk for cancer and other diseases. Studies suggest that reducing inflammation with drugs such as aspirin and non-aspirin NSAIDs (non-steroidal anti-inflammatory drugs) may reduce overall cancer risk. However, studies of whether these drugs influence ovarian cancer risk have been inconclusive.

A team led by Drs. Britton Trabert and Nicolas Wentzensen of NIH’s National Cancer Institute (NCI) investigated associations between ovarian cancer and aspirin, non-aspirin NSAIDs, or acetaminophen use. The researchers analyzed data from 12 large studies that together included nearly 8,000 women with ovarian cancer and 12,000 without. The results were reported in the February 2014 issue of the Journal of the National Cancer Institute.

Overall, 18% of the women reported using aspirin regularly (at least once per week), 24% used non-aspirin NSAIDs regularly, and 16% used acetaminophen. Women who reported daily aspirin use had a 20% lower risk of ovarian cancer than those who used aspirin less than once per week. Results for non-aspirin NSAID use, which include a wide variety of drugs, were less clear. The scientists observed a 10% lower ovarian cancer risk among women who used NSAIDs at least once per week compared with those who used NSAIDs less frequently.  However, the finding was not statistically significant—it may be due to chance. Acetaminophen, which relieves pain but doesn’t reduce inflammation, wasn’t associated with reduced ovarian cancer risk.

These findings add ovarian cancer to a growing list of cancers that might be prevented by aspirin use. “Our study suggests that aspirin regimens, proven to protect against heart attack, may reduce the risk of ovarian cancer as well,” Trabert says. “However intriguing our results are, they should not influence current clinical practice. Additional studies are needed to explore the delicate balance of risk-benefit for this potential chemopreventive agent, as well as studies to identify the mechanism by which aspirin may reduce ovarian cancer risk.”

The scientists caution that, despite the potential benefits of a daily aspirin regimen, it should only be undertaken with a doctor’s approval. Side effects of daily aspirin use include gastrointestinal bleeding and hemorrhagic stroke.