OBJECTIVES:
* Assess the balance of risks and benefits in prolonging the duration of adjuvant tamoxifen by at least 5 years in patients with curatively treated breast cancer who have already had about 5 years of adjuvant tamoxifen.
OUTLINE: This is a randomized study. After about 5 years of adjuvant tamoxifen, recurrence-free patients are randomized to stop tamoxifen treatment immediately or to continue tamoxifen treatment for at least 5 more years.
Patients are followed annually.
PROJECTED ACCRUAL: Approximately 20,000 patients will be accrued for this study.
