Researchers are seeking to recruit 22,000 women for a study that will compare the benefits and risks of tamoxifen and raloxifene, two drugs which are believed to reduce an individual’s risk for breast cancer.
A study of 13,000 women has already established that tamoxifen can reduce breast cancer risk by one half. However, tamoxifen also has many negative side effects including increased risk of uterine cancer, blood clots in the large veins and lungs, and greater risk for stroke. Raloxifene, which is used by many older women to fight osteoporosis, has also been found effective in reducing breast cancer risk, and causes fewer serious side effects.
The study, which will be led by the National Surgical Adjuvant Breast and Bowel Project (NSABBP), will include a select group of women who have a high risk of getting breast cancer, are willing to take raloxifene or tamoxifen for five years, are post-menopausal, and are at least 35 years old. Researchers expect that they expect to screen 200,000-300,000 women in order to find 22,000 appropriate subjects.
A statement released by NSABBP Chair Norman Wolmark read, “Studies of raloxifene suggest is has the potential to prevent breast cancer. The only way to prove that potential is in a clinical trial in which the risks and benefits of raloxifene are directly compared with the risk and benefits of tamoxifen.”
The National Cancer Institute will fund the study, which is expected to cost between 75 and 100 million dollars over 10 years.