Daily aspirin use reduced ovarian cancer risk by 20%

Aspirin use was associated with a reduced risk for ovarian cancer, with daily and low-dose aspirin use linked to the most dramatic risk reductions, according to results of a pooled analysis.

Britton Trabert, PhD, of the hormonal and reproductive epidemiology branch in the division of cancer epidemiology and genetics at NCI, and colleagues evaluated data from 12 population-based, case-controlled ovarian cancer studies conducted from 1992 to 2007.

The analysis included 7,776 patients and 11,843 controls. Eighteen percent of study participants reported regular aspirin use, defined as at least one weekly usage. Twenty-four percent reported regular use of non-aspirin NSAIDs and 16% reported regular acetaminophen use.

Overall, researchers found regular aspirin use was associated with a reduced ovarian cancer risk (OR=0.91; 95% CI, 0.84-0.99).

Studies that considered frequency and dosage indicated daily aspirin reduced the risk for ovarian cancer by 20% (OR=0.80; 95% CI, 0.67-0.96), and low-dose aspirin — defined as ˂100 mg a day — reduced the risk by 34% (OR=0.66; 95% CI, 0.53-0.83).

Researchers also found regular use of non-aspirin NSAIDs reduced ovarian cancer risk; however, the association was not statistically significant (OR=0.90; 95% CI, 0.77-1.05). Doses ˃500 mg a day furthered reduced the risk (OR=0.76; 95% CI, 0.64-0.91).

Acetaminophen was not associated with a reduced ovarian cancer risk (OR=0.99; 95% CI, 0.88-1.12).

Despite these results, researchers noted the risks associated with regular aspirin use, such as peptic ulcers, upper gastrointestinal bleeding and hemorrhagic stroke.

“Our study suggests that aspirin regimens, proven to protect against heart attack, may reduce the risk of ovarian cancer as well,” Trabert said in a press release. “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.”