Aspirin May Reduce Ovarian Cancer Risk

Women who take aspirin regularly may be at a reduced risk for ovarian cancer, the results of a new meta-analysis suggest.

Ovarian cancer, the most lethal gynecological cancer, may be related to chronic inflammation. However, previous studies that have assessed aspirin use and cancer risk have not delivered conclusive results on the relationship between the medication and ovarian cancer. A new meta-analysis, published online on February 6, 2014, in the Journal of the National Cancer Institute, analyzed data from population-based studies to help determine the association between the use of aspirin, non-aspirin non-steroidal anti-inflammatory drugs (NSAIDS), and acetaminophen and the risk of developing ovarian cancer.

The pooled analysis included data from 12 case-control studies participating in the Ovarian Cancer Association Consortium that were conducted from 1992 to 2007. Medication use was self-reported in all of the studies and was defined as regular if patients took aspirin, other NSAIDs, or acetaminophen at least one time per week. Medication use was also categorized by frequency, dose, and duration. The researchers adjusted for age, race, body mass index, oral contraceptive use, the number of times the women gave birth, and family history of breast or ovarian cancer.

Of 7776 patients with invasive ovarian cancer and 11,843 control patients included in the analysis, 18% reported regular use of aspirin, 24% reported regular use of non-aspirin NSAIDs, and 16% reported regular use of acetaminophen. The results indicated that regular aspirin use was associated with a reduced risk of ovarian cancer. Among 7 studies that reported frequency of use, daily use of aspirin was associated with a 20% decrease in ovarian cancer risk. In 3 studies that included dose information, low-dose aspirin use (less than 100 mg per day) was associated with a 34% reduction in ovarian cancer risk.

Use of NSAIDs was also associated with a reduced risk of ovarian cancer, although this reduction in risk was not statistically significant. In the 3 studies with dose information, taking high-dose (at least 500 mg per day) non-aspirin NSAIDs was associated with a 24% reduction in the risk for ovarian cancer. The results indicated no relationship between acetaminophen use and ovarian cancer risk either overall or when considered based on different levels of dose, duration, and frequency.

The authors of an accompanying editorial note that although these results add to evidence showing the potential protective benefits of aspirin, the question of when health care providers should recommend aspirin to help prevent ovarian cancer is still unknown. Aspirin use may be beneficial for women at high risk for ovarian cancer, but both benefits and risks of long-term medication use need to be evaluated, they suggest.

“For ovarian cancer, we now need to mount key epidemiological studies that will address this question for defined high-risk patients (with germline BRCA mutations and strong family histories) as well as the risk/benefit in women not defined to be at high risk,” they write. “Are we at the tipping point to initiate these trials? We believe so.”