Estrogen for Triple Negative Breast Cancer

Inclusion Criteria:

histologically or cytologically confirmed breast cancer which is metastatic.
A formalin-fixed paraffin embedded tumor block (preferred) or unstained slides must be available from either a prior biopsy of the primary tumor or a metastatic site. .
Primary tumor or metastatic biopsy lacking estrogen and progesterone receptor and Her2 negative
Patients must have measurable disease.
Eastern Cooperative Oncology Group performance status 0-1.
Patients with bone metastasis at baseline must agree to treatment with intravenous bisphosphonates
Subjects may have had 0-4 lines of prior systemic chemotherapy or targeted therapy regimens administered for treatment of their metastatic breast cancer.
Age >18 years
Life expectancy of greater than 3 months.
Patients must have adequate organ and marrow function as defined below:

Exclusion Criteria:

systemic chemotherapies, targeted therapies or radiotherapy for their cancer within 2 weeks prior to entering the study
Patients receiving any other investigational agents for breast cancer treatment.
Patients with known brain metastases are excluded 3.2.4 History of allergic reactions attributed to compounds of similar chemical or biologic composition to estradiol.
Patients with any condition of the gastrointestinal tract that is expected to result in an inability to take oral medication
Dysfunctional or post-menopausal vaginal bleeding.
Uncontrolled hypercalcemia/hypocalcemia
Prior history of or active thrombophlebitis, cerebral vascular accident, myocardial infarction, deep venous thrombosis or pulmonary embolism.
History of or active hepatic adenoma.
Uncontrolled intercurrent illness
Pregnant women are excluded from this study
Patients with bone metastasis are excluded if they are unable to receive intravenous bisphosphonate therapy due to the risk for developing hypercalcemia.