DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed adenocarcinoma of the breast

  • Locally advanced or metastatic disease

• Measurable disease

  • No bone disease only
• No history of brain metastases unless controlled with radiotherapy or surgical resection for ≥ 6 months before study entry

• Hormone receptor status:

  • Estrogen receptor- OR progesterone receptor-positive

PATIENT CHARACTERISTICS:

Age

• 18 and over

Sex

• Female

Menopausal status

• Postmenopausal, as defined by 1 of the following:

  • Prior bilateral oophorectomy
  • Prior bilateral ovarian irradiation
  • No spontaneous menstrual bleeding within the past 12 months
  • Age 55 and over AND prior hysterectomy without oophorectomy
  • Age 54 and under AND prior hysterectomy without oophorectomy (or status of ovaries is unknown) AND documented follicle-stimulating hormone level in postmenopausal range

Performance status

• ECOG 0-2

Life expectancy

• At least 3 months

Hematopoietic

• Granulocyte count ≥ 1,000/mm^3
• Platelet count ≥ 100,000/mm^3

Hepatic

• Bilirubin ≤ 1.5 times upper limit of normal (ULN)
• AST and ALT ≤ 2.5 times ULN

Renal

• Creatinine ≤ 1.5 times ULN

Other

• No prior allergic reaction attributed to compounds of similar chemical or biologic composition to study drugs
• No prior allergic reaction to sulfonamides
• No active peptic ulcer disease
• No active infection
• No other medical condition that would preclude study participation
• Able to swallow oral medication

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• No prior chemotherapy for metastatic or recurrent disease

Endocrine therapy

• No prior endocrine therapy for metastatic disease

  • Prior adjuvant tamoxifen allowed
• No prior aromatase inhibitors
• No prior hormonal therapy for recurrent disease
• No other concurrent hormonal therapy

Radiotherapy

• See Disease Characteristics
• See Menopausal status
• No concurrent radiotherapy

Surgery

• See Disease Characteristics
• See Menopausal status

Other

• No concurrent fluconazole or lithium

• No concurrent aspirin, non-steroidal anti-inflammatory drugs, or other cyclooxygenase-2 inhibitors

  • Concurrent chronic cardioprotective low-dose aspirin allowed
• No other concurrent investigational agents