DISEASE CHARACTERISTICS:

• Histologically confirmed noninvasive or small invasive breast cancer

  • Low or intermediate grade (ductal carcinoma in situ, T1, or T2) OR
  • Estrogen and/or progesterone receptor positive
  • Largest mass no greater than 5 cm
  • Clustered microcalcifications as only abnormality allowed with no upper size limit
  • If no distinction between mass and microcalcifications, size as 1 lesion
• Lumpectomy or mastectomy must be planned for 2-6 weeks from start of study
• No evidence of metastases from any malignancy

• Hormone receptor status:

  • Estrogen and progesterone receptor positive (unless low or intermediate grade tumor)

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Sex:

• Female

Menopausal status:

• Postmenopausal by one of the following:

  • Prior oophorectomy
  • Over age 50 with prior hysterectomy, ovaries remaining
  • Uterus and ovaries intact and no menstrual period for more than 3 months

Performance status:

• Not specified

Life expectancy:

• Not specified

Hematopoietic:

• Platelet count greater than 100,000/mm^3
• Hemoglobin greater than 10 g/dL
• Absolute granulocyte count greater than 1,000/mm^3

Hepatic:

• Albumin greater than 3 g/dL
• Bilirubin less than 1.5 mg/dL
• AST less than 100 U/L
• Alkaline phosphatase less than 200 U/L

Renal:

• Creatinine less than 1.5 mg/dL

Cardiovascular:

• No history of deep vein thrombosis

Pulmonary:

• No prior pulmonary embolus

Other:

• Not pregnant or nursing

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• At least 1 year since prior chemotherapy

Endocrine therapy:

• At least 1 year since prior aromatase inhibitors, antiestrogens, or LH agonists/antagonists
• No concurrent hormone replacement therapy or oral contraceptives (from time of randomization)

Radiotherapy:

• Not specified

Surgery:

• See Disease Characteristics

Other:

• No concurrent treatment for other malignancy