Blood Levels of Tumor Cells in Predicting Response in Patients Receiving First-Line Chemotherapy for Stage IV Breast Cancer
Blood Levels of Tumor Cells in Predicting Response in Patients Receiving First-Line Chemotherapy for Stage IV Breast Cancer
RATIONALE: Measuring blood levels of tumor cells in patients with breast cancer may help
 doctors predict how patients will respond to treatment.

 PURPOSE: This laboratory study is looking at blood levels of tumor cells in predicting
 response in patients receiving first-line chemotherapy for stage IV breast cancer.
OBJECTIVES:

 Primary

 -  Predict the overall and progression-free survival of patients with stage IV breast
 cancer by measuring the rate of circulating tumor cells (CTC) before the second course
 of chemotherapy.

 Secondary

 -  Predict overall and progression-free survival of these patients by measuring the rate of
 CTC before the start of chemotherapy, at the first tumor evaluation, and after 2-3
 courses of chemotherapy.

 -  Correlate the detection of CTC with tumor markers, clinical response, and radiological
 response.

 -  Study the changing status of HER-2 in CTC in patients receiving trastuzmab (Herceptin®).

 OUTLINE: This is a multicenter study.

 Blood samples are collected at baseline, before the second course of chemotherapy, before the
 third or fourth course of chemotherapy, and when progressive disease is diagnosed (before
 second-line treatment is initiated). Circulating tumor cells from the blood samples are
 examined by immunofluorescence.

 Patients are followed periodically for up to 3 months.
DISEASE CHARACTERISTICS:

 -  Diagnosis of stage IV breast cancer

 -  Measurable or evaluable disease

 -  Scheduled to receive first-line chemotherapy with or without trastuzumab (Herceptin®),
 depending on HER-2 status

 -  Histologic block available for confirming pathologic diagnosis and measuring HER-2
 status via FISH

 PATIENT CHARACTERISTICS:

 -  Life expectancy > 3 months

 -  No other cancer in the past 5 years except for basal cell skin cancer or epithelial in
 situ cancer of the cervix

 -  No geographic, social, or psychiatric reasons that would make treatment impossible

 PRIOR CONCURRENT THERAPY:

 -  No prior chemotherapy for metastatic disease