Radiation Therapy With or Without Optional Tamoxifen in Treating Women With Ductal Carcinoma in Situ

OBJECTIVES:

- Compare the efficacy of whole breast radiotherapy vs observation with or without
optional tamoxifen in decreasing or delaying the appearance of local failure (both
invasive and in situ) and preventing the need for mastectomy in women with good-risk
ductal carcinoma in situ (DCIS) of the breast.

- Compare distant disease-free survival of patients treated with these regimens.

OUTLINE: This is a randomized, multicenter study. Patients are stratified according to age
(under 50 vs 50 and over), final path margins (negative vs 3-9 mm vs at least 10 mm),
mammographic size of primary (no greater than 1 cm vs greater than 1 cm to 2.5 cm), nuclei
grade (low vs intermediate), and tamoxifen use (yes vs no). Patients are randomized to 1 of 2
treatment arms.

- Arm I: Patients undergo observation and may receive optional oral tamoxifen once daily
(at the discretion of the physician) for 5 years.

- Arm II: Beginning within 12 weeks after final surgery, patients receive radiotherapy to
the whole breast once daily, 5 days a week, for 3.5-5.5 weeks. Patients may receive
optional tamoxifen as in arm I.

Patients are followed every 3 months for 1 year, every 6 months for 2 years, and then
annually thereafter.

PROJECTED ACCRUAL: A total of 1,790 patients will be accrued for this study within 6 years.

DISEASE CHARACTERISTICS:

- Ductal carcinoma in situ (DCIS) of the breast detected by mammogram at the time of
diagnosis

- Unicentric

- Lesions ≤ 2.5 cm

- Low nuclei grade (NG1) or intermediate nuclei grade (NG2) with necrosis in < one
third of the involved ducts

- Inked margins ≥ 3 mm

- Clinically node negative

- Non-palpable

- No suspicious areas on post-operative mammogram taken within 12 weeks after final
surgery

- No bloody nipple discharge

- No more than 12 weeks since prior final surgery (arm II only)

- Hormone receptor status:

- Not specified

PATIENT CHARACTERISTICS:

Age:

- 26 and over

Sex:

- Female

Menopausal status:

- Not specified

Performance status:

- Not specified

Life expectancy:

- Not specified

Hematopoietic:

- Not specified

Hepatic:

- Not specified

Renal:

- Not specified

Other:

- Not pregnant or nursing

- No active connective tissue disorders (e.g., lupus or scleroderma)

- No prior malignancy within the past 5 years except adequately treated basal cell or
squamous cell skin cancer or carcinoma in situ of the cervix

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Not specified

Chemotherapy:

- No prior chemotherapy

Endocrine therapy:

- No other concurrent hormonal therapy (e.g., raloxifene, hormone replacement therapy,
or birth control pills)

Radiotherapy:

- No prior radiotherapy

Surgery:

- See Disease Characteristics