Anastrozole in Treating Postmenopausal Women With DCIS or Stage I-III Breast Cancer

DISEASE CHARACTERISTICS:

• Histologically confirmed breast cancer meeting 1 of the following criteria:

  • Ductal carcinoma in situ (DCIS)

  • Invasive carcinoma

    • Stage I-III disease

• Must have undergone breast cancer surgery within the past 6 months, including any of the following:

  • Mastectomy or lumpectomy with or without radiation
  • Sentinel node and/or axillary node dissection
  • Re-excision of lumpectomy margins

• Intact contralateral breast

  • No prior radiation therapy or mastectomy
  • Prior biopsies allowed

• Hormone receptor status:

  • Estrogen and/or progesterone receptor-positive tumor by immunohistochemical staining

PATIENT CHARACTERISTICS:

Sex

• Female

Menopausal status

• Postmenopausal, defined as 1 of the following:

  • At least 60 years of age
  • Less than 60 years of age and amenorrheic ≥ 12 months prior to study entry
  • Less than 60 years of age, amenorrheic for < 12 months prior to day 1, and luteinizing hormone (LH) and follicle stimulating hormone (FSH) values within postmenopausal range
  • Less than 60 years of age, without a uterus, and LH and FSH values within postmenopausal range
  • Underwent prior bilateral oophorectomy
  • Underwent prior radiation castration AND amenorrheic for ≥ 6 months

Performance status

• ECOG 0-2

Life expectancy

• Not specified

Hematopoietic

• Not specified

Hepatic

• Not specified

Renal

• Not specified

PRIOR CONCURRENT THERAPY:

Chemotherapy

• No prior or concurrent adjuvant chemotherapy for breast cancer

Endocrine therapy

• No prior aromatase inhibitor
• At least 6 weeks since prior and no concurrent tamoxifen

• At least 6 weeks since prior and no concurrent hormone replacement therapy

  • Concurrent low-dose, local vaginal estrogen in the form of either a conjugated estrogen ring or other similar product (e.g., Estring® or Vagifem®) allowed
• At least 6 weeks since prior and no other concurrent selective estrogen receptor modulators (e.g., raloxifene)

Radiotherapy

• See Disease Characteristics

Surgery

• See Disease Characteristics
• No contralateral breast implant

Other

• Concurrent bisphosphonates allowed at the discretion of the treating oncologist

• No concurrent consumption of soy supplements

  • Concurrent routine dietary consumption of soy-containing foods allowed
• No other concurrent investigational or commercial drugs or therapies for the treatment of DCIS or invasive breast cancer