Drugs like the anti-estrogen tamoxifen and the selective estrogen receptor modulater (SERM) raloxifene have been shown to reduce breast cancer risk and possibly be an important part of a person's breast cancer prevention strategy . In fact, tamoxifen has been approved for breast cancer prevention for more than a decade now. Despite this, few women at high risk for breast cancer choose to adopt this particular breast cancer prevention approach, partly due to fears of adverse side-effects and costs of the medication. Therefore, researchers continue to search for a breast cancer prevention drug that might be more well-accepted by individuals at high risk for breast cancer.
One new drug under study is lasofoxifene, a SERM designed for the treatment of osteoporosis. Earlier this year, results of a large clinical trial reported that lasofoxifene treatment reduced risks of vertebral fracture, nonvertebral fracture, ER-positive breast cancer, coronary heart disease events, and stroke. A new breast cancer research study using all 8,500+ volunteers from the first study examined the impact of lasofoxifene treatment on total breast cancer risk. These researchers showed that
After taking lasofoxifene (0.5 mg/day) for 5 years, total breast cancer risk was reduced by 79%.
Risk of estrogen receptor-positive (ER[+]) invasive breast cancer was reduced by 83%.
The benefits of lasofoxifene on breast cancer risk were greater for women with higher than average blood levels of estradiol.
The results of this study suggest that lasofoxifene, like tamoxifen and raloxifene, can reduce breast cancer risk and might one day be a viable option for the prevention of breast cancer in women at high risk for breast cancer. In addition to showing a reduction for the risk for total breast cancer and ER[+] invasive breast cancer, the studies on lasofoxifene to date indicate that daily treatment with 0.5 mg/day also reduces a postmenopausal woman's risk for heart disease events, strokes, vertebral fractures and non-vertebral fractures. While lasofoxifene has been approved in Europe for the treatment of osteoporosis, it has not yet been approved by the U.S. FDA for the treatment of osteoporosis due to concerns regarding its safety profile.
Should future studies continue to show the benefits of lasofoxifene for osteoporosis and breast cancer risk, while showing a better safety profile, we might one day see a new breast cancer prevention drug available for use. In the meantime, there is plenty we can do as individuals to reduce our breast cancer risk, including leading a healthy lifestyle that incorporates plenty of exercise and a healthy, well balanced diet rich in breast cancer fighting foods.