• Comparison of levels of peripheral blood (PB) circulating endothelial cells (CEC) and plasma angiogenic factors between patients with active, measurable breast cancer vs prior history of breast cancer with no evidence of active disease [ Designated as safety issue: No ]
  

• Correlation of CEC and plasma angiogenic factors with response to tumor to a chemotherapy regimen [ Designated as safety issue: No ]
  

OBJECTIVES:

Primary

• To compare peripheral blood (PB) concentrations of circulating endothelial cells (CEC) in women with measurable, active breast cancer to PB concentrations of CEC in a control population of women with a history of breast cancer who are currently without evidence of active disease.

Secondary

• To compare in women with measurable breast cancer the relationship between PB concentrations of CEC prior to and at 3 and 6 weeks following initiation of a new chemotherapy or hormonal therapy, and correlate these values with clinical response to treatment to determine if CEC can be used as a tumor marker or indicator of disease burden.
• To compare PB concentrations of CEC to levels of plasma proteins associated with angiogenesis, including vascular endothelial growth factor, in women with active or a prior history of breast cancer.

OUTLINE: Peripheral blood and plasma samples are collected for analysis of circulating endothelial cells (CEC) and angiogenic growth factor levels. Blood samples from patients initiating a new chemotherapy or hormonal therapy for breast cancer are collected at baseline and at 3 and 6 weeks following the start of treatment. CEC are quantified via flow cytometry and plasma angiogenic markers are assessed via ELISA.

PROJECTED ACCRUAL: A total of 100 patients with active, measurable breast cancer and 100 patients with a prior history of breast cancer will be accrued for this study.