OBJECTIVES:
Primary
* Compare ipsilateral tumor relapse and breast cancer metastases in women with completely excised low-risk estrogen receptor- or progesterone receptor-positive ductal carcinoma in situ of the breast receiving adjuvant tamoxifen or anastrozole and treated with adjuvant radiotherapy vs observation alone.
* Compare the quality of life of patients treated with these regimens.
Secondary
* Determine the minimal surgical margins required to minimize the local recurrence rate in patients treated with these regimens.
* Identify molecular markers that predict ipsilateral tumor recurrence in patients treated with these regimens.
OUTLINE: This is a randomized, multicenter study. Patients are stratified according to participating center. Patients are randomized to 1 of 2 treatment arms.
All patients receive adjuvant tamoxifen or anastrozole for 5 years.
* Arm I: Patients undergo radiotherapy 5 days a week for 3 or 5 weeks.
* Arm II: Patients undergo observation alone. Quality of life is assessed at baseline, at 6 months, and then at 1, 2, and 5 years.
Patients are followed every 6 months for 1 year and then annually for up to 10 years.
Peer Reviewed and Funded or Endorsed by Cancer Research UK
PROJECTED ACCRUAL: A total of 2,000 patients (1,000 per treatment arm) will be accrued for this study within 5 years.
