According to the National Cancer Institute (NCI), initial results of the Study of Tamoxifen and Raloxifene (STAR) Trial show that raloxifene (also known as Evista®) is as good as tamoxifen in helping prevent invasive breast cancer in postmenopausal women who are at high risk for the disease. Raloxifene might also have fewer serious side effects.
Tamoxifen and raloxifene are both referred to as selective estrogen receptor modulators, or SERMS for short. Both drugs interfere with the effects of estrogen in the body, which, among other effects, can help prevent breast cancer. Raloxifene is newer than tamoxifen and is commonly used to help prevent and treat osteoporosis in postmenopausal women.
Tamoxifen (also known as Nolvadex®) is a drug that has been used for years as part of the treatment for breast cancer. In more recent years it has also been used effectively to help prevent breast cancer in women who are at high-risk. The question remains as to whether or not similar drugs might also be able to prevent breast cancer and with fewer serious side effects. The initial results of the STAR Trial suggest that raloxifene might do just that. However, further research is needed to confirm these initial findings.
Details of the Study
The STAR Trial is a large study supported by the NCI to compare raloxifene with tamoxifen and its role in breast cancer prevention. The trial included nearly 20,000 postmenopausal women at high risk for developing breast cancer. Women who participated in the study were assigned to take either tamoxifen or raloxifene once a day for five years. Results showed that both groups had a 50 percent reduction in invasive breast cancer compared with those women at high risk for the disease who did not take either medicine. Specifically, 9,745 women took raloxifene and 167 developed breast cancer. In the tamoxifen group there were 9,726 women and 163 developed breast cancer.
Both drugs have serious potential side effects. Tamoxifen can cause blood clots and can also cause cancer of the uterus. Raloxifene can also cause blood clots. In this study, however, women who took raloxifene had 36 percent fewer cases of uterine cancer and 29 percent fewer blood clots compared with the women who took tamoxifen. The incidence of heart attacks, strokes, and bone fractures was the same in both groups.
It should be noted that tamoxifen was better than raloxifene at preventing lobular carcinoma in situ and ductal carcinoma in situ, which are also referred to as noninvasive breast cancers. Raloxifene did not protect against these noninvasive breast cancers in this study.
Further clinical trials are needed to confirm these results. But these initial results look promising. Every woman should talk to her doctor about her risk for developing breast cancer. If she is at high risk, she should discuss the appropriate available preventive measures. |
