Breast Cancer Prevention Study Confirms Drug Effectiveness
June 1, 2010
Jackson, Mich. — Allegiance Health - Ray H. Clark Cancer Research Program, Allegiance Hematology/Oncology, participated in a STAR P-2 Trial in Breast Cancer Prevention.
An update of the results of the study of Raloxifene and Tamoxifen, (STAR P-2 trial in breast cancer prevention) shows that the drug Raloxifene (initially used to prevent and treat osteoporosis in postmenopausal women) improved its effectiveness against noninvasive breast cancer, caused significantly less endometrial cancer and was significantly less toxic than Tamoxifen. After 81 months of follow-up, although Raloxifene was slightly less effective against invasive breast cancer, it still maintained strong efficacy.
Allegiance Health - Ray H. Clark Cancer Research Program, Allegiance Hematology/Oncology, participated in the STAR Study, one of the largest breast cancer prevention clinical trials ever conducted. STAR enrolled 19,490 postmenopausal women who were at increased risk for the disease in the follow-up study. At Allegiance Health, 31 of women were enrolled, and in Michigan, 1032 were enrolled.
This long-term trial is coordinated by the National Surgical Adjuvant Breast and Bowel Project (NSABP), a network of cancer research professionals, and is sponsored by the National Cancer Institute, part of the National Institutes of Health.
“These results help clarify that both Raloxifene and Tamoxifen are good preventive choices for high risk postmenopausal women depending largely on a woman’s risk factors,” said Norman Wolmark, MD, NSABP chairman. “The results of this longer-term study should encourage wide spread acceptance of Raloxifene and greater acceptance of Tamoxifen for breast cancer prevention among postmenopausal women at an elevated risk, ultimately reducing the burden of breast cancer on the public health.”
John Axelson, MD, primary investigator for the P-2 trial at Allegiance Health, said, “The STAR P-2 trial is just one example of the many cancer prevention and treatment trials that Allegiance Hematology/Oncology has been involved in since 1978. Patients in our community are able to participate in these state-of-the-art trials right here in Jackson.”
Improved detection and treatment of breast cancer have not eliminated the need for better prevention of this disease, which accounted for approximately 192,000 new cancer cases and 40,000 cancer deaths in the U.S. in 2009. Although the selective estrogen-receptor modulator (SERM) tamoxifen became the first U.S. Food and Drug Administration (FDA) approved agent for reducing breast cancer risk, it did not gain wide acceptance for prevention largely because it increased endometrial cancer and thromboembolic events. Raloxifene was approved by the FDA for breast cancer risk reduction following its pronounced efficacy in preventing invasive, but not noninvasive, breast cancer in the Phase III Study of Tamoxifen and Raloxifene. Initial STAR toxicity profiles favored Raloxifene (e.g. significantly reduced thromboembolic events and, non-significantly, reduced endometrial cancer) over Tamoxifen. Differences in the two drugs made it imperative to conduct longer-term follow-up to clarify their relative merits in regard to a host of benefits and risks, but particularly in regard to noninvasive breast cancer.