Postmenopausal women at high risk for developing breast cancer may soon have another preventive option besides the drug tamoxifen.

Tamoxifen has not been widely embraced because of potential side effects including uterine cancer and blood clots.

Results from one of the largest breast cancer prevention studies ever conducted reveals that raloxifene—a drug used for the prevention and treatment of osteoporosis in postmenopausal women—works just as well as tamoxifen at preventing breast cancer in high-risk postmenopausal women.

Specifically, results showed that both drugs reduced the risk of developing invasive breast cancer by 50 percent.

In addition, women taking 60 mg per day of raloxifene and followed for an average of four years experienced 36 percent fewer uterine cancers and 29 percent fewer blood clots than women taking 20 mg per day of tamoxifen.

Know Your Risk

Medical oncologist James Gould, M.D., chairman of the comprehensive cancer program at Western Baptist, said knowing your risk is important.

“Education is key,” said Gould. “Know if you’re at risk and practice early detection by having routine mammograms and administering monthly breast self-exams.”

Risk factors include the following:

• Being older than 40 with a family history of breast cancer in a mother, sister or daughter.
• Having a history of abnormal cells on breast biopsies.
• Starting your period at age 11 or younger.
• Starting menopause at a later age than normal.
• Never being pregnant or having your first child after age 35.
• Gaining weight after menopause and/or after the age of 60.

Gould said patients should speak with their physicians to determine if this preventive medication is appropriate.

The U.S. Preventive Services Task Force said the best candidates for a medication prevention strategy using tamoxifen or raloxifene are:

• In their 40s, at high risk of developing breast cancer and aren’t prone to developing blood clots.
• In their 50s, at high risk of developing breast cancer, aren’t prone to developing blood clots and don’t have a uterus.