Frequent aspirin use is associated with lower ovarian cancer risk regardless of the presence of most other ovarian cancer risk factors, according to a meta-analysis published online 22 July in the Journal of Clinical Oncology.

Lauren M Hurwitz, PhD, from the National Cancer Institute in Rockville, Maryland, US and colleagues used individual-level data from 17 studies to examine the association between frequent aspirin use and ovarian cancer risk.

Based on nine cohort studies from the Ovarian Cancer Cohort Consortium (2600 cases) and eight case-control studies from the Ovarian Cancer Association Consortium (5726 cases), the researchers found that frequent aspirin use was associated with a 13% reduction in ovarian cancer risk, with no significant heterogeneity by study design or histotype.

This association was not seen among women with endometriosis; however, consistent risk reductions were seen among all other subgroups defined by ovarian cancer risk factors, including women with two or more risk factors (relative risk, 0.81).