The tissue obtained in this protocol will be used for genome-wide examination of DNA, RNA expression profiling, proteomic analyses, isolation and analyses of normal and cancer stem cells, isolation and analyses of circulating tumor cells, possible analyses of immune cells, and possible analyses of serum factors. The tissue may also be used to develop patient-specific cell culture models or mouse xenograft models of breast cancer for biologic study of tumor progression and metastases and for therapeutic testing. In general, the tissue will be used in studies that will molecularly classify tumors, identify prognostic markers, identify potential therapeutic markers, identify potential treatment targets, and help us better understand the biology and specific role played by different tumor cells in the metastatic process.

The ultimate goal is to use molecular analyses to improve the diagnosis and treatment of breast cancer.

Inclusion Criteria:People eligible for this study include anyone older than 18 years who is undergoing one of the following procedures: core needle or surgical breast biopsy, lumpectomy, mastectomy, axillary lymph node surgery, breast reduction surgery, or ductal lavage or ductoscopy. Patients who have had breast cancer in the past who are currently free of disease or who have a breast cancer recurrence are also eligible. All patients who participate must be able to understand and sign the informed consent. Although most patients will be female, any males undergoing the above procedures are also eligible for this study. Exclusion Criteria:Any patient who is less than 18 years old, who is unable to understand the informed consent, or not undergoing the above procedures will be excluded from this research.