Study Evaluates Benefits And Risks Of Tamoxifen And Raloxifene For Reducing Risk Of Breast Cancer
Tamoxifen is a selective estrogen receptor modulator (SERM) that has been used to treat both early and advanced breast cancer for more than three decades, according to background information in the article. Raloxifene is a second-generation SERM currently used as a medication for the prevention and treatment of osteoporosis. But clinical trials have shown it may have a role in reducing the risk of invasive breast cancer in postmenopausal women.
Victor G. Vogel, M.D., M.H.S., from Magee-Womens Hospital, University of Pittsburgh School of Medicine, and colleagues from The National Surgical Adjuvant Breast and Bowel Project (NSABP), conducted a randomized clinical trial (Study of Tamoxifen and Raloxifene or STAR trial) at nearly 200 clinical centers throughout North America. Patients were 19,747 postmenopausal women with an average age of 58.5 years with an increased five-year breast cancer risk. The study patients were randomized to receive oral tamoxifen (20 mg/day) or raloxifene (60 mg/day) over five years.
"There were 163 cases of invasive breast cancer in women assigned to tamoxifen and 168 in those assigned to raloxifene (incidence, 4.30 per 1,000 vs. 4.41 per 1,000)," according to the study authors. There were fewer cases of noninvasive breast cancer in the tamoxifen group (57 cases) than in the raloxifene group (80 cases), while there were 36 cases of uterine cancer with tamoxifen and 23 with raloxifene; however, neither of these differences were statistically significant. No differences were found for other invasive cancer sites, for ischemic heart disease events, or for stroke. Thromboembolic events (such as blood clots in the lung or deep veins) occurred less often in the raloxifene group and there were fewer cataracts and cataracts surgeries in that group. The number of osteoporotic fractures in the two groups was similar. There were no differences in the total number of deaths or in causes of death.
The authors suggest that primary care physicians, who are the most involved in preventive care, have not prescribed tamoxifen because it is viewed as a toxic cancer drug. "In contrast, raloxifene is well known to the primary care community and is widely prescribed for the prevention and treatment of osteoporosis in postmenopausal women. More than 500,000 women in the United States are currently taking raloxifene, the majority of whom are older and at lower risk of breast cancer than are the women in the STAR trial."
In conclusion, the researchers write: "This trial confirms the previously reported benefit of raloxifene in reducing the risk of invasive breast cancer and indicates that raloxifene is as active as tamoxifen in this regard. If raloxifene is approved by the Food and Drug Administration for the prevention of breast cancer, primary care physicians may be more willing, given their experience with raloxifene, to prescribe it for breast cancer chemoprevention than they have been to prescribe tamoxifen."
Clare Collins
JAMA and Archives Journals
http://www.jamamedia.org/
Studiul evalueazã beneficiile ºi riscurile Tamoxifen ªi Raloxifene pentru reducerea riscului de cancer de sân - Study Evaluates Benefits And Risks Of Tamoxifen And Raloxifene For Reducing Risk Of Breast Cancer - articole medicale engleza - startsanatate