ICI 182780 in Treating Women With Metastatic Breast Cancer

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed adenocarcinoma of the breast * Progressive local-regional or metastatic disease * Unconfirmed new or progressive multiple pulmonary nodules or unequivocal radiographic evidence of multiple bone metastases allowed * At least 1 measurable lesion * At least 20 mm by CT scan or MRI OR at least 10 mm by spiral CT scan * Nonmeasurable disease includes the following: * Bone lesions * Leptomeningeal disease * Ascites * Pleural/pericardial effusions * Lymphangitis cutis/pulmonis * Inflammatory breast disease * Abdominal masses not confirmed and followed by imaging techniques * Cystic lesions * Disease progression after prior third-generation aromatase inhibitor (e.g., anastrozole, exemestane, letrozole, or vorozole) * Failed no more than 1 prior additive hormonal therapy (e.g., aromatase inhibitor with or without tamoxifen) * Disease recurrence identified no more than 12 months since the last prior adjuvant tamoxifen treatment * Oophorectomy, ovarian radiotherapy, and luteinizing hormone-releasing hormone (LH-RH) analogs not considered hormonal therapy regimens * No brain or leptomeningeal metastases * No hepatic metastases involving more than one-third of the liver * No symptomatic pulmonary lymphangitic disease * Evidence of hormone sensitivity as defined by: * Relapse after at least 12 months of adjuvant hormonal treatment * Tumor remission or stabilization before progression for at least 6 months after prior hormonal therapy for advanced disease * Postmenopausal as defined by one of the following: * At least 12 months since last menstrual period * 4-11 months since last menstrual period and follicle-stimulating hormone (FSH) in the postmenopausal range * Prior castration and castrate FSH levels within the postmenopausal range * Hysterectomy without oophorectomy (FSH in postmenopausal range if age 60 and under) * Hormone receptor status: * Estrogen-receptor and/or progesterone-receptor positive * At least 10 fmol/mg cytosol protein OR * Positive by immunohistochemistry PATIENT CHARACTERISTICS: Age: * 18 and over Sex: * Female Menopausal status: * See Disease Characteristics * Postmenopausal Performance status: * ECOG 0-2 Life expectancy: * At least 3 months Hematopoietic: * WBC at least 2,000/mm\^3 * Platelet count at least 100,000/mm\^3 * No history of bleeding diathesis Hepatic: * See Disease Characteristics * Bilirubin no greater than 0.8 mg/dL above upper limit of normal (ULN) * INR no greater than 1.6 * No hepatitis B or C * No severe hepatic impairment Renal: * Calcium no greater than 10% above ULN * Creatinine no greater than 1 mg/dL above ULN * No severe renal impairment Cardiovascular: * No unstable or uncompensated cardiac condition Pulmonary: * No unstable or uncompensated respiratory condition Other: * HIV negative * No AIDS * No other severe condition or systemic disease that would preclude study participation PRIOR CONCURRENT THERAPY: Biologic therapy: * Prior trastuzumab (Herceptin) allowed Chemotherapy: * Prior adjuvant chemotherapy allowed * No more than 1 prior chemotherapy regimen for metastatic disease Endocrine therapy: * See Disease Characteristics * More than 4 weeks since prior estrogen replacement therapy * More than 3 months since prior LH-RH analogs * No other prior additive hormonal therapy except third-generation aromatase inhibitors or tamoxifen Radiotherapy: * See Disease Characteristics * Concurrent radiotherapy for control of bone pain or other reasons due to established bone lesions allowed if radiotherapy field is no more than 30% of bone marrow Surgery: * See Disease Characteristics Other: * More than 4 weeks since prior investigational drug for breast cancer * No concurrent long-term warfarin * Concurrent bisphosphonates allowed if dose stable * Concurrent long-term antiplatelet therapy allowed