SoFEAA Partially Blind Phase III Randomised Trial of Faslodex +/- Concomitant Arimidex Compared With Exemestane in Post-menopausal Women With ER+ or PR+ Locally Advanced/Metastatic Breast Cancer Following Progression on Non-steroidal AIs

Study start date: March 26, 2004

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed adenocarcinoma of the breast * Locally advanced or metastatic disease * Metastatic disease must be measurable or evaluable * Patients with bone only metastases are eligible provided there is an evaluable site of bone metastasis that can be followed by x-ray, MRI, or CT scan * Relapsed or progressed during prior treatment with single-agent nonsteroidal aromatase inhibitor (NSAI)\*, meeting either of the following criteria: * NSAI given as adjuvant therapy that lasted ≥ 12 months * Achieved an objective complete response, partial response, or stable disease that lasted ≥ 6 months after prior first-line therapy with NSAI for locally advanced or metastatic disease * Chemotherapy as part of the first-line therapy given before initiation of NSAI allowed NOTE: \*Patients are required to continue to take NSAI until beginning of study treatment. * No rapidly progressive visceral disease (i.e., lymphangitis carcinomatosa or diffuse hepatic involvement) * Hormone receptor status: * Estrogen receptor (ER) and/or progesterone receptor positive tumor * No ER-unknown disease PATIENT CHARACTERISTICS: Sex * Female Menopausal status * Postmenopausal, as defined by 1 of the following criteria: * Age 60 and over * Age 45 to 59 AND ≥ 12 months since last menstrual period with no prior hysterectomy * Any age with prior bilateral oophorectomy Performance status * WHO 0-2 Life expectancy * More than 3 months Hematopoietic * Neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * No thrombocytopenia * Hemoglobin ≥ 10 g/dL Hepatic * AST and ALT ≤ 2.5 times upper limit of normal (ULN) * Alkaline phosphatase ≤ 5 times ULN (unless due to bone metastases) * No liver disease Renal * Creatinine \< 1.97 mg/dL Other * No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer or carcinoma in situ of the cervix PRIOR CONCURRENT THERAPY: Chemotherapy * See Disease Characteristics * Prior neoadjuvant or adjuvant chemotherapy allowed Endocrine therapy * See Disease Characteristics * Prior tamoxifen as neoadjuvant or adjuvant therapy allowed * No systemic corticosteroids that lasted \> 15 days within the past 4 weeks Other * More than 4 weeks since prior investigational drugs * Concurrent bisphosphonates for bone metastases allowed provided bisphosphonate therapy has been established for ≥ 6 months * Concurrent initiation of bisphosphonate allowed provided patient has soft tissue or visceral metastases as the measurable or evaluable target lesion * No concurrent anticoagulant therapy * No concurrent unlicensed noncancer investigational agents