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Study of Tamoxifen and Raloxifene (STAR) Trial

  • Updated: 02/02/2011

The information and links on this page are no longer being updated and are provided for reference purposes only.

STAR-At-A Glance


Main ObjectiveSTAR was designed to determine whether the osteoporosis drug raloxifene is as effective in reducing breast cancer risk as tamoxifen, with fewer side effects.
Enrollment Accrual PeriodJuly 1999 – November 2004
ParticipantsA total of 19,737 women:
  • 93.4% white
  • 2.5% African American
  • 2.0% Hispanic/Latina
  • 2.1% other minorities
InterventionWomen were randomly assigned to take either 20 mg of tamoxifen and a placebo or 60 mg raloxifene and a placebo daily for five years.
Criteria for Participation
  • General good health
  • 35 and over
  • Women
  • Postmenopausal at high risk for breast cancer based on the Gail risk model
Study SitesMore than 500 in the U.S., Puerto Rico and Canada.
Additional Study ObjectivesInvestigators are assessing rates of invasive breast cancer, noninvasive breast cancer, uterine cancer, deep vein thrombosis, pulmonary embolism, bone fractures, stroke, cataracts, ischemic heard disease, all other cancers, and overall deaths. Quality of life factors (including hot flashes, which both drugs can trigger) and cognitive function in older women are also being examined.

Related Pages

  • Breast Cancer Home Page
    NCI's gateway for information about breast cancer.
  • U.S. Task Force: Chemoprevention of Breast Cancer
    The U.S. Preventive Services Task Force has issued two recommendations concerning the use of prescription medicines such as tamoxifen in the prevention of breast cancer.
  • Estrogen Receptors, Tamoxifen, and Raloxifene
    Describes the hormone estrogen and its receptor. Explains the relationship of estrogen and its receptor to breast cancer and the risks and benefits of reducing cancer risk with drugs called antiestrogens and selective estrogen receptor molecules (SERMs).