MeritCare Part of International Breast Cancer Study
Initial results of the study of tamoxifen and raloxifene (STAR), show that the drug raloxifene, currently used to prevent and treat osteoporosis in postmenopausal women, works as well as tamoxifen in reducing breast cancer risk for women at increased risk of the disease. In addition, women taking raloxifene have not experienced some of the serious side effects known to occur with tamoxifen.
According to Dr. Ralph Levitt, oncologist/hematologist, and principal investigator for the study, MeritCare Roger Maris Cancer Center, "This is major news for all postmenopausal women in our region that are at high risk of developing breast cancer."
In STAR, both drugs reduced the risk of developing invasive breast cancer by about 50 percent. In addition, within the study, women who were prospectively and randomly assigned to take raloxifene daily, and who were followed for an average of about four years, had 36 percent fewer uterine cancers and 29 percent fewer blood clots than the women who were assigned to take tamoxifen. Uterine cancers, especially endometrial cancers, are a rare but serious side effect of tamoxifen. Both tamoxifen and raloxifene are known to increase a woman's risk of blood clots.
STAR enrolled 19,747 postmenopausal women who were at increased risk of the disease. Participants were randomly assigned to receive either 60 mg of raloxifene (Evista®) or 20 mg of tamoxifen (Nolvadex®) daily for five years.
"In 1998, the landmark Breast Cancer Prevention Trial showed that tamoxifen could reduce the risk of invasive breast cancer in premenopausal and postmenopausal women by nearly 50 percent," said Norman Wolmark, M.D., NSABP chairman. "Today, we can tell you that for postmenopausal women at increased risk of breast cancer, raloxifene is just as effective, without some of the serious side effects known to occur with tamoxifen."
Participants in STAR are now receiving information about which drug they were taking. Women assigned to raloxifene will continue to be provided with the drug until they have completed five years of treatment. Those women assigned to tamoxifen can choose to continue taking tamoxifen or to receive raloxifene to complete their five years of treatment.
Women who participated in STAR were postmenopausal, at least 35 years old, and had an increased risk of breast cancer as determined by their age, family history of breast cancer, personal medical history, age at first menstrual period, and age at first live birth. Before participating in the study, the women were instructed about the potential risks and benefits of tamoxifen and raloxifene and then were asked to sign an informed consent.
For more information about STAR, including links to media materials and a fact sheet, visit http://www.cancer.gov/star.
The photo on the top right includes Dr. Ralph Levitt, oncologist ,and Mary Ann Smith, STAR study participant, as they answer questions at a MeritCare news conference announcing the results of a major breast cancer prevention trial.