A recent study partly funded by OCRA, and published in the Journal of Clinical Oncology, has shown that frequent aspirin use (defined as more than six times per week for more than six months) is associated with a reduction in ovarian cancer risk. Three members of OCRA’s Scientific Advisory Committee – Dr. Andrew Berchuck (also a grantee), Dr. Celeste Leigh Pearce, and Dr. Shelley S. Tworoger – were among the authors of this study.
Chemoprevention is the use of certain drugs or other substances to prevent cancer. Preventative aspirin use has pointed to cardiovascular benefits, and those same studies noted a decrease of gynecologic cancers. But there were too few ovarian cancer diagnoses within those trial populations to draw inferences.
It had been thought that chronic inflammation may have played a role in ovarian cancer, and so anti-inflammatory medications, like aspirin, may lower the risk of development of the disease by inhibiting the cyclooxygenase enzymes. But how that played out amongst populations with a greater risk for ovarian cancer, as well as those with factors that have shown to decrease risk, was not clear.
The authors looked at individual-level data from 17 studies – nine from the Ovarian Cancer Cohort Consortium (with a total of 2,600 cases of ovarian cancer among 491,651 women at risk) and eight from the Ovarian Cancer Association Consortium (including 5,726 cases) – and put them against ovarian cancer risk factors, including endometriosis, obesity, family history, nulliparity (not having given birth), oral contraceptive use and tubal ligation.
The authors meta-analyzed the data to determine specific risk reduction levels against each risk factor, which showed some variation in levels, but determined that frequent aspirin use was associated with a 13% overall risk reduction of ovarian cancer. This study, the largest-to-date on frequent aspirin use and ovarian cancer, shows an association, regardless of the presence of risk factors.