Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically confirmed metastatic breast cancer Bidimensionally
measurable disease Lesion at least 2 cm in at least 1 diameter No failure with prior
adjuvant antiestrogens within the first 12 months of treatment No progression of disease
during therapy with prior aromatase inhibitors or selective estrogen receptor modulators
(SERMs) (including SERMs for prevention of osteoporosis) No history of known CNS
metastases No bone metastases as only tumor manifestation Hormone receptor status:
Estrogen receptor and/or progesterone receptor positive

PATIENT CHARACTERISTICS: Age: 18 and over Sex: Female Menopausal status: Postmenopausal
Performance status: ECOG 0-1 Life expectancy: At least 12 weeks Hematopoietic: Hemoglobin
at least 9 g/dL Platelet count at least 100,000/mm3 WBC at least 2,000/mm3 Hepatic: AST
and ALT no greater than 2.5 times upper limit of normal (ULN) Bilirubin no greater than
2.5 times ULN Renal: Creatinine no greater than 2.0 mg/dL Other: No significant
neurological dysfunction including seizures or clinical signs of other significant
neurological diseases No other active malignancy within the past 5 years except basal cell
skin cancer or carcinoma in situ of the cervix No contraindication to toremifene or its
excipients or any of the excipients in atamestane Not pregnant or nursing

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior cytotoxic
chemotherapy for metastatic disease At least 6 months since prior adjuvant chemotherapy No
concurrent chemotherapy Endocrine therapy: See Disease Characteristics No prior hormonal
therapy for metastatic disease At least 12 months since prior adjuvant antiestrogens No
concurrent SERMs or estrogenic or androgenic hormones No other concurrent aromatase
inhibitors Radiotherapy: No concurrent radiotherapy except for palliation for bone
metastases Surgery: Not specified Other: No prior enrollment in this study At least 30
days since prior investigational drugs No other concurrent investigational drugs
Concurrent bisphosphonates for bone metastases allowed