Inclusion Criteria

DISEASE CHARACTERISTICS: Diagnosis of metastatic breast cancer Measurable or evaluable
disease Postmenopausal No spontaneous menses for at least 5 years (including
chemotherapy-induced amenorrhea) Spontaneous menses within the past 5 years allowed if
amenorrheic for at least 12 months and LH and FSH in postmenopausal normal range
(including chemotherapy-induced amenorrhea) Bilateral oophorectomy Radiotherapy castration
and amenorrheic for at least 3 months Hormone receptor status: Estrogen-receptor (ER)
and/or progesterone-receptor (PR) positive No ER and PR negative or unknown tumors

PATIENT CHARACTERISTICS: Age: 18 and over Sex: Female Menopausal status: See Disease
Characteristics Performance status: Karnofsky 50-100% WHO 0-2 Life expectancy: Not
specified Hematopoietic: Not specified Hepatic: Not specified Renal: Corrected serum
calcium less than 11.6 mg/dL Other: No known hypersensitivity to any of the constituents
of the study drug No history of noncompliance to medical regimens No unreliability Not
pregnant or nursing Fertile patients must use effective contraception HIV negative

PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent anticancer immunotherapy or
biological response modifiers Chemotherapy: See Disease Characteristics Prior adjuvant or
neoadjuvant chemotherapy with adjuvant tamoxifen allowed No concurrent anticancer
chemotherapy Endocrine therapy: See Chemotherapy No other concurrent anticancer endocrine
therapy (including steroids) Radiotherapy: See Disease Characteristics No concurrent
radiotherapy to sole site of disease Concurrent radiotherapy to a limited area (e.g., for
painful disease) allowed Surgery: See Disease Characteristics No prior adrenalectomy or
hypophysectomy Other: At least 30 days since prior systemic investigational drugs At least
7 days since prior topical investigational drugs No other concurrent investigational drugs
Concurrent bisphosphonates (e.g., zoledronic acid) for bone metastasis allowed