A Single Arm Phase II Study of Pharmacologic Dose Estrogen in Postmenopausal Women With Hormone Receptor-Positive Metastatic Breast Cancer After Failure of Sequential Endocrine Therapies

Inclusion Criteria:

- Histologically confirmed estrogen and/or progesterone receptor-positive breast cancer
metastatic breast cancer

- Clinically determined evaluable disease

- Post-menopausal woman

- Previous clinical benefit from prior anti-estrogen therapies and subsequent failure
of at least 2 prior endocrine therapies.

- May have had chemotherapy for adjuvant &/or metastatic disease.

- May have had radiation therapy but not to the only site of disease.

- Ecog performance status
- Life expectancy of > 6 months

Exclusion Criteria:

- Chemotherapy or radiotherapy within 1 week of beginning treatment in the clinical
trial

- Brain metastasis

- Prior history of or active thrombophlebitis, deep venous thrombosis or pulmonary
embolus

- Current vaginal bleeding

- Hypercalcemia or hypocalcemia

- History of or active hepatic adenoma

- No other malignancies within the past 5 years with the exception of curatively
treated basal cell or squamous cell carcinoma of the skin or carcinoma in-situ of the
cervix