Aspirin and Breast Cancer Prevention

Over the past decade, breast cancer chemoprevention has made substantial progress, particularly with selective estrogen receptor modulators and aromatase inhibitors. A new generation of chemopreventive agents modulating the non-endocrine biochemical pathways has been studied so far, including the 100-year-old drug aspirin. Commonly known as pain-reliever, aspirin may also influence breast carcinogenesis through a number of mechanisms, including decreased production of prostaglandins, which can inhibit angiogenesis and inhibit apoptosis, inhibition of the cyclo-oxygenase enzymatic pathways and stimulation of the AMPk pathway leading to decreased proliferation and increased autophagy. Long-term follow-up of randomized trials of aspirin in prevention of vascular events showed that daily aspirin reduced the incidence of colorectal cancer and several other cancers, including a borderline effect on breast cancer incidence. In the present review, we discuss the potential role aspirin in breast cancer prevention comparing data from observational studies with those from the randomized trials.