Inclusion Criteria:

- 3.2 Radiographic evidence of new or progressive metastatic breast cancer by CT
chest/abdomen/pelvis and bone scan, or by PET scan, with 3 or more distant sites of
metastasis involving 2 or more organ sites appropriate for biopsy.

- 3.3 Histologic documentation of metastatic invasive breast cancer with metastasis to
a distant organ site (lung, liver, pleural/peritoneal, skin (>20 cm away from
breast), and/or bone) by core needle or excisional biopsy - patients may consent to
study prior to diagnostic procedure.

- 3.4 Estrogen Receptor, Progesterone Receptor, and HER2 status must be available,
either from archived primary tumor, or from diagnostic biopsy.

- 3.5 Archived primary tumor must be obtainable and on-site by the date of
registration, or primary tumor must be intact and biopsy-able.

- 3.5 Patients with multi-centric or bilateral disease are eligible if the target
lesions meet the other eligibility criteria.

- 3.6. The subject must agree to undergo and tolerate the research biopsy(ies) and
blood draw.

- 3.7. Prior chemotherapy, endocrine therapy, or radiotherapy with therapeutic intent
is allowed.

- 3.8. Women or men > age 18.

- 3.9. Ability to give informed consent.

- 3.10 Normal PT/INR

- 3.11 Negative pregnancy test or beyond reproductive potential.

- 3.12 Medical evaluation by medical oncology within 4 weeks.

- 3.13 Non-smokers only are eligible, see exclusion criteria #4.

Exclusion Criteria:

- 1. Brain-only metastatic disease.

- 2. Poor venous access (unable to tolerate 19-gauge needle).

- 3. Unable to tolerate blood draw or research biopsy procedures.

- 4. Current smokers, smoked at all within the last 10 years, or have a lifetime
smoking history greater than equal to 5 pk years.