Aspirin and NSAIDs: effects in breast and ovarian cancers

The purpose of this review is to provide clinicians with current concepts regarding prevention for breast and ovarian cancers. Specifically, this review will provide evidence for the chemoprevention of breast and ovarian cancers with analgesics, such as aspirin, non-steroidal anti-inflammatory drugs (NSAIDs), and acetaminophen.

Preclinical investigations provide consistent evidence that NSAIDs effectively inhibit the carcinogenesis of epithelial tumors, especially colon and gastrointestinal tract cancers, but also breast and ovarian cancers. The anti-tumor effects of aspirin and other NSAIDs are thought to arise primarily from an inhibition of cyclooxygenase-2. Recent studies have also supported a link between cyclooxygenase-2-mediated prostaglandin production and estrogen biosynthesis via the aromatase enzyme. In addition, some epidemiologic studies have reported that hormone-receptor-positive breast tumors are more responsive to aspirin, which is consistent with these preclinical findings. A recent large-scale randomized trial found, however, that low-dose aspirin in healthy women did not reduce the incidence of either breast or ovarian cancers.

There is significant preclinical evidence to support the chemopreventive effects of aspirin, NSAIDs, and acetaminophen. Given the conflicting data from observational studies and the null results from a limited number of randomized trials, it is, however, too early to suggest that the regular use of these analgesics could help prevent breast or ovarian cancers.