Heterogeneous expression of tumor-associated genes in disseminated breast cancer cells.

Background: Gene expression profiles were determined to demonstrate heterogeneity of viable disseminated tumor cells (DTC) in the blood of breast cancer patients.

Patients And Methods: All patients (n = 48) suffered from metastatic disease (M1) and were treated with chemotherapy and/or Herceptin, respectively. Blood samples were analyzed by a DTC detection assay consisting of immunomagnetic tumor cell selection combined with expression profiling of the tumor-associated transcripts GA733-2, MUC-1, HER-2 and Claudin-7.