RANDOMIZED PHASE II STUDY IN FIRST LINE HORMONAL TREATMENT FOR METASTATIC BREAST CANCER WITH EXEMESTANE OR TAMOXIFEN IN POSTMENOPAUSAL PATIENTS

Study start date: May 1, 1996

DISEASE CHARACTERISTICS: Histologically or cytologically proven adenocarcinoma of the breast that is metastatic and progressive or locally recurrent and inoperable At least one bidimensionally measurable or evaluable lesion Lytic bone lesions on x-ray/CT scan, surrounded by calcified bone, and at least 1 cm Bidimensionally measurable extraosseous disease required for patients on bisphosphonates The following are not considered evaluable: Previously irradiated lesions Lymphangitic spread Ascites Blastic bone lesions Pleural effusions No rapidly progressive disease for which hormonal therapy is not indicated No massive visceral disease (i.e., more than one third of any organ) No brain metastases Hormone receptor status: Estrogen receptor positive or progesterone receptor positive, defined by 1 of the following: At least 10 femtomoles H3-estrogen or at least 20 femtomoles H3 progesterone binding per mg of cytosol protein by DCC or sucrose density method At least 0.10 femtomoles H3-estrogen or at least 0.20 femtomoles H3-progesterone binding per mg of DNA by IF/EIA technique Positive immunohistochemistry noted on pathology report Unknown receptor status eligible provided: Disease-free interval of at least 2 years since adjuvant therapy or initial surgery (if no adjuvant therapy), including most recently treated tumor in bilateral breast cancer if status unknown in one primary tumor PATIENT CHARACTERISTICS: Age: 18 and over Sex: Female Menopausal status: Postmenopausal by 1 of the following: Natural menopause and more than 1 year since last menstrual period (LMP) Radiation-induced oophorectomy and more than 1 year since LMP Chemotherapy induced menopause if: At least 1 year since LMP (+ 1 year post-tamoxifen) Serum FSH and LH and plasma estradiol levels in postmenopausal range LHRH-induced amenorrhea Surgical castration Patients under age 56 with prior hysterectomy and 1 or both ovaries intact or tamoxifen-induced amenorrhea with at least 12 months since prior tamoxifen must have postmenopausal serum FSH and LH and plasma estradiol concentrations Performance status: ECOG (WHO) 0-2 Hematopoietic: Absolute neutrophil count at least 1,500/mm^3 Platelet count at least 100,000/mm^3 Hepatic: Bilirubin less than 1.5 times upper limit of normal (ULN) SGOT/SGPT less than 2.5 times ULN (less than 5 times ULN with liver metastases) Renal: Creatinine less than 1.5 times ULN Cardiovascular: No deep venous thrombosis Other: No mental incapacitation No severe concurrent disease No prior or concurrent malignancy except curatively treated carcinoma in situ of the cervix or basal cell or squamous cell skin cancer PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent immunotherapy Chemotherapy: See Disease Characteristics At least 3 weeks since chemotherapy for metastatic disease and recovered No more than 1 prior chemotherapy regimen for metastatic disease Prior adjuvant chemotherapy allowed if disease free for at least 6 months No concurrent chemotherapy Endocrine therapy: No prior hormonal therapy for advanced disease (e.g., tamoxifen or LHRH agonists) Prior adjuvant tamoxifen allowed if disease free for at least 6 months No other concurrent hormonal therapy, including steroids Radiotherapy: Recovered from toxic effects of prior radiotherapy Concurrent palliative radiotherapy, including whole brain irradiation, allowed Surgery: See Disease Characteristics No prior ovariectomy for advanced disease Other: No other concurrent investigational drugs Concurrent bisphosphonates allowed if short term (7 days) for hypercalcemia due to suspect tumor flare or if on prior bisphosphonates with bidimensionally measurable extraosseous lesion